Bluebird and Small Cavity Nester Conservation
Sialis - Bluebirds and other small cavity nesters
 
bluebirds

printer friendly page

Feeding Mealworms

Also see Raising Mealworms | Landscaping for Bluebirds | Feeding Suet

Quick tips: Buy mealworms online for the best price, train bluebirds to come to the feeder, and offer about 15 worms/bird/day in a glass/plastic dish 100 feet away from the nestbox inside a special feeder that excludes larger birds and protects worms from sun and rain.

See about mealworms and where to get them, storing, dried mealworms, training bluebirds to come to a feeder, hand feeding, feeding raisins, how many to feed, mealworm size, feeder location, the ideal feeder, feeder plans, a "mobile" DIY feeder, preventing mealworm escape, supplementing calcium, winter feeding, dried mealworms and waxworms, recipe for Purple Martins, saving them for the Blues, hawk concerns, Assassin Bugs, and links to more info on feeding.

Also see landscaping for bluebirds, feeding crickets to birds, suet recipes, and where to buy feeders.


Offering mealworms to bluebirds may have enticed them to stick around and nest on my trail, and may also encourage second and tFemale bluebird feeding fledgling.  Photo by Leah Sollidayhird broods. (If you don't have bluebirds around, offering mealworms will not make them magically appear.) I feed mealworms near my house for my own enjoyment. Feeding bluebirds lets us observe their behavior and health, and enables better photography. It is a thrill when the parents bring their young to the feeder several weeks after fledging. In Central Ohio, a trail monitor of more rural trails in Paula Ziebarth's area reported finding 43 dead EABL in his boxes at his first box check. On her suburban trails, there were no dead EABL found. We are finding EABL to be frequent visitors to feeding stations in the suburbs in central Ohio here and she believes that the human handouts (mealworms and suet) saved lives that winter.

I also sometimes put up a mobile mealworm feeder near an active bluebird nest, to help nestlings survive periods of cold/wet weather, enable parents to stay near the nest to defend it, and assist single parents. It's possible (though not proven) that baby bluebirds fed mealworms fledge earlier, are healthier, and have a higher survival rate when receiving a steady diet of mealworms for the first two weeks after hatching. Adults also need extra food during the breeding season due to increased exposure and the energy drain associated with feeding young. The protein that mealworms provide helps rapidly growing nestlings. However, moderation is key, as mealworms are low in calcium and have a tough exoskeleton that can be hard for young birds to digest.

Training: Bluebirds need to learn to come to a feeder. They will learn to come for mealworms in response to a whistle, bell, call, or even a banging door. Pretty soon they will have YOU trained to feed them when they are hungry.

I train them by

  1. putting mealworms in a cat food can or small plastic container (like the cut off bottom of a clean plastic soda bottle) with a tack on the nestbox roof once, or in a brightly colored bowl near where blues are perching (e.g., under a telephone wire they hang out on). If the worms are actively moving this increases the likelihood that the bluebirds will notice them. A piece of bright blue cloth or flagging might get their attention. Putting some bright red berries that bluebird eat may also attract their attention to the feeder.
  2. As soon as they find and eat some worms, they should be hooked. Then I move the can to the top of the feeder, which is placed near the nestbox or perching spot. (I tried putting the mealworms in a bowl on the ground during training, and ended up teaching robins to come to the feeder, where they proceeded to eat me out of house and home.)
  3. You may need to leave the feeder open for a bit to get them used to going inside.
  4. Once bluebirds have figured out the feeder, you can move it short distances every day or so until it's in the desired location.

Also see Fred's instructions with photos.

About Mealworms and where to get them: Mealworms are the larvae of the flightless darkling beetle (Tenebrio molitor). Large mealworms from Reptile Foods relative to quarter. Photo by Bet ZimmermanThey are not slimy, although at room temperature they wiggle a lot. (Some people don't like to handle them, and use a scoop or tea strainer to collect them to put out in the feeder.)

Mealworms are high in protein (~20-48%), especially when fed crushed dry dog/cat food. It's generally not "necessary" to provide mealworms, but it's fun - and expensive - mail order mealworms cost about $40/10,000 plus shipping (shop around, prices vary depending on volume, size and shipping costs). See information on how to raise your own mealworms.

Mealworms are generally fed live. Bluebirds will usually not eat the dead, black ones. They MAY eat freeze dried or roasted mealworms if no other choices are available, or if they are mixed in with suet. More info. Bluebirds do relish live waxworms, but they are considerably more expensive than mealworms. They may prefer them to mealworms because of higher fat content. See info on superworms.

Size:I buy the large size of mealworm, since they're the same price as small or medium, although they may be a bit too big for nestlings the first 3-4 days after hatching. The larger the mealworm, the larger the exoskeleton, which is not readily digested by mealworms. "Giant" mealworms are not recommended, as they may be fed hormones which prevents normal metamorphosis, causing the larvae to continue growing without ever pupating.

See a list of mail order mealworm suppliers - I prefer suppliers that donate a portion of the proceeds can be directed to nonprofit bird conservation organizations, who sell juicy, healthy worms. Some suppliers offer a discount to NABS members. Be sure to order about five days ahead of time so you don't run out (although in a pinch, I've read you can feed raw hamburger, canned cat food, or cottage cheese.) Try to pick a supplier that offers a live delivery guarantee. If the Post Office or other carrier leaves them in a hot place for even 1/2 hour, they can cook, and summer shipments can be problematic.

Storing Mealworms: As long as the worms are at least 1" from the container, and the sides are vertical and slippery (glass or plastic), they won't get out. Store the worms in the refrigerator, where they go somewhat dormant and will last for several months. If your family is too grossed out by the concept, you can keep them in a small dorm-sized refrigerator. If you store them outside of the refrigerator, don't put them in too small of a container as they will overheat and die. Also, if the weather is warm, they will pupate and turn into beetles.

When a shipment arrives, I dump and shake everything out into a big white plastic garbage bag which the mealworms can not cling to (otherwise they end up on the floor or glommed on to newspaper, etc.), and then put them in a Tupperware container with holes poked in the top (again, when cold, the worms become dormant and don't climb up and out).

Mealworms need food and moisture. To make the mealworms more nutritious for bluebirds (so they are not just mostly empty calories), you can add some wheat germ, powdered milk or part brewers yeast, or ground up dog food to the bedding. Add an inch or two of wheat bran or cornmeal (easier to sift out worms) and thin slices of potato or apple (for moisture - but don't let it get moldy), or kale or yams (which are more nutritious). Don't let it get moldy, or the worms will get gunked up in the decay and croak. Fawzi Emad straps a sponge or to the lid of his containers and doesn't add any other source of moisture (see picture.) You can also put a moist sponge inside an open plastic baggie so the bedding doesn't get wet. It's a good idea to take them out of the frig once a week and let them eat (to bulk up for the blues) for a few hours. If they start to smell like ammonia, sift out the "frass" and add fresh bedding.

I also add some layers of newspaper or egg cartons to enable them to spread out. It also makes it easier to collect them. (Mealworms also like to hide - my husband wasn't too happy to find some escapees inside his wallet one day....) If you want to get rid of shed skins that pile up, you can bring the worm container outside and use a blow dryer set on low:cool, or use some masking tape.

Other Foods like Raisins: Fruits contain sugars and carbohydrates which come in handy during the cold, as they help maintain body temperature. If you want to train bluebirds to eat raisins (stewed or otherwise), you might try mixing them in with the mealworms. Some bluebirds won't touch raisins, others relish them. Whole raisins are a bit too big for bluebirds, so they should be chopped. Cover the raisins with water, bring the pot to a boil and simmer for 5 minutes, then drain, cool, and chop them up for feeding, storing extras in the refrigerator.

CURRANTS: You can also feed currants (smaller than raisins. Baking currants are sticky, so wash them off, and then dry and refrigerate. You can also try freeze dried blueberries, or other berries such as dogwood. If you chop them up in a food processor, freeze them first so they don't gum up the blades.

CRICKETS can be offered for variety, but should be chilled for several hours so they do not hop off. Also, freezing softens the barbs on the back legs. See more on feeding crickets.

To offer a more varied diet, Keith Kridler used to hang a 100 watt bare light bulb at night, over a five gallon bucket with about 1" of water. You can add a steel cone or funnel to keep them from flying out. However, you may catch some insects birds won't eat.

Bluebirds can also learn to eat suet during colder months. See recipes. Many landlords find that bluebirds are not interested in commercially available "Bluebird Nuggets."

Dried Mealworms and Dried/Roasted Waxworms: I have not tried feeding these, but several people report that bluebirds had no interest in dried mealworms or waxworms (e.g., from F.M. Brown & Sons.) Another person reported they did take "bird grub" (roasted caterpillars of the Bee Moth) by Audubon Workshop. Others have had bluebirds eat them readily if live ones were not provided, in winter and during breeding season, feeding them to young. Rehydrating dried mealworms may make them more attractive. If given a choice, I've been told they prefer them to dried mealworms. You can soak them in hot water for 15 minutes, or can also try soaking them in a few drops of vegetable oil before putting them in the feeder.

Some dried mealworms may be grown and packaged in other countries like China, where there were problems in 2007 with cat food contamination.

Winter Feeding: In August when birds may need higher calories foods like berries, or when temperatures drop below 40 degrees F, blues may lose interest in mealworms. However, I saw a male gobble down 10 on a December morning when it was 18 degrees F out. One bluebirder offers mealworms in a container that sits in the water of a heated birdbath, which keeps the mealworms mobile and possibly makes them more attractive. Heated mealworm feeders are available, but some are outrageously expensive. Judith Mangireo puts out a shallow dish of live mealworms on a small heating pad used for small animals that live outdoors (available at cozywinters.com.)  This is much cheaper than mealworm warmer cup. Put a very thin bed of bran at the bottom of the saucer and the worms are happy.

Bluebirds may also learn to eat suet and scrambled eggs. Suet is a good winter food - see recipes.

Some people freeze mealworms to offer to adults after nesting is complete.

Feeder Location: Do not put feeders too close to nestboxes (except temporarily during training.) The feeder should be about 100' away from a nestbox so predators and nestbox competitors are not attracted to the box. If you use a feeding bowl on on top of or on the nestbox pole (which I don't recommend), only put in enough worms to be eaten immediately (~ 5 per bird) while you are nearby. Mockingbirds are sometimes a problem, as they may drive bluebirds away. Try moving the feeder away from where mockingbirds nest (e.g., conifers). Also see concerns about hawks. I do not place mealworm feeders next to seed feeders, as it just teaches other birds to eat mealworms (which are expensive.)

How many to feed: Fawzi Emad recommends offering about 15 mealworms per bluebird per day. I've seen each blue eating about 3-10 per visit. NABS indicates that "because they should be used as a supplemental food, mealworms should only be offered once or twice a day unless poor weather conditions dictate more frequent feeding. A hundred or so worms offered morning and evening would be adequate for a pair with a box of nestlings." Feeding smaller amounts twice a day is a good idea to ensure that bluebirds get some, and to prevent other species from "discovering" the feeder. One of the nice things about mealworms is that there is no waste left behind - no seeds or shells.

Offering an unlimited supply of mealworms is probably NOT recommended, as the nestlings need a varied diet. See supplementing with calcium.

Occasionally after nestlings have fledged you may find a few mealworms in the nesting material. Not to worry - they probably got missed by the babies during feeding.

Sometimes yellow jackets will go after mealworms. If you limit quantities so that the ones you put out are eaten right away, this shouldn't be a problem.

At the end of the nesting season, don't buy too many, as sometimes bluebirds disappear after the last brood fledges.

Training Birds to Eat from Your Hand: It may not be wise to train birds to eat from your hand, as they may become too tame and thus vulnerable to humans who are not well-meaning as you. Some degree of fear helps wild birds survive. If you choose to try this, do wash your hands afterwards, especially before touching pet birds. Also, keep posted on Avian Flu and other bird diseases that can be transmitted to humans.

  1. Spread a big blue cloth over a lawn chair.
  2. Put the pan with worms in it. Call the birds or give a signal (like a whistle.) Do this for a couple of days.
  3. Then YOU sit in the chair, spread the blue cloth over your lap, add the worm pan and here come the birds.
  4. After a few trips, remove the tray and put worms in your hand.

Saving them for the Blues: Avoid letting worms fall to the ground when filling a feeder, as you may inadvertently "train" other birds like robins, and attract fire ants if they are in your area. Other birds that enjoy mealworms include Tufted Titmice, Carolina Wrens, nuthatches, chickadees, red bellied woodpeckers, Blue and Scrub Jays, mockingbirds, Towhees and Phoebes. Mockingbirds are notorious for quickly learning to come to a feeder for mealworms, so you may wish to use a style that excludes larger birds. Your best bet in this case is probably a cage style feeder like this one sold by The Bluebird Nut or one by Evergreen that puts mealworms out of reach. If House Sparrows discover your mealworm feeder during breeding season (when they feed insects to you), try a Magic Halo or other control methods.

Winter feeding: To keep mealworms alive, active and warm, some people use a heated mealworm feeder. This type of feeder is expensive. Connie from Ft. Wayne IN came up with an alternative: put an instant heat for 7+ hours hand warmer under a small piece of padding and place the mealworm bowl over it.

Hawk Concerns: Hawks sometimes learn to hang out by a bird feeder, looking for easy prey. Cooper's hawks and American Kestrels in particular might nab a bluebird at a feeder, and a Red-shoulder Hawk might get a fledgling. These raptors are native species, and have to eat and feed their own families. However, to minimize the risk to bluebirds you attract to a feeder, locate feeders where there is some overhead protection from dive bombing, and consider minimizing feeding when fledglings are out. A plastic dome over the feeder will prevent birds from being nabbed while they are actually feeding or perching. Stop feeding for two weeks if a raptor is hunting frequently in your area. Plant native shrubs for cover (low growing thorny bushes will prevent cats from hanging under it.) See What can I do about hawks preying on songbirds at my feeder? for more info.

Feeder styles and plans: Several feeder plans are available (e.g. Fawzi Emad's) in addition to the simple Do It Yourself (DIY) one described below.

You can also buy feeders specially designed for bluebirds. (Bluebird Love used to make a heated feeder for $190 with shipping! - more reasonably priced plastic models may be available. See Suppliers. ) In my opinion, the best designs:

  • exclude larger birds (starlings, jays and mockingbirds) and mammals. A large floor helps so they can't reach in, and it also helps if there is a way to keep the food in the center of the floor (again so large birds can't tip things their way)
  • shed rain (which drowns mealworms) and protect mealworms from sun (e.g., with a roof - sun fries mealworms).
  • last for years. Mesh should be coated so it does not rust.
  • are readily entered by bluebirds (no struggling, little fear, offering multiple choices for both entrance and exit). If the feeder has mesh on some or all sides, check to see that the openings are truly 1.5" big, or larger bluebirds (especially during winter) may have to struggle to enter.
  • are easily filled and cleaned (any interior food holder should be removable for cleaning and filling, room to stick your hand in to fill, ideally only requiring one hand to open so you can hold food in the other).
  • can also be used to feed suet or berries.

Feeder options:

  • A jailhouse style using dowels is popular. Bluebirders (including Pam Ford) were involved in designing a Duncraft feeder that looks nice, and allows for photography of feeding birds. Some are too narrow and large birds can hang on the edges and reach in to snag food. Those with wooden dowels are subject to squirrel chewage (metal or lucite dowels are preferable).
  • Cage style: The Bluebird Nut makes a wire feeder with a roof that has a removable container for either suet or mealworms. Some bluebirds refuse to enter through wire mesh. Sticking a branch through the cage might help them get accustomed to it.
    • You can make your own with white wire storage cubes available at department stores - just make sure the openings are 1.5" - see photos. Panels can be snapped together, and you can use plastic wire straps to make a door hinge, and a clamp or other device (like a toy carabiner) to hold the door closed. (Thanks Donna of VA)
  • An alternative is a feeder that has wood on either end with holes in it, and then mesh on the sides, which gives the birds a choice of entries.
  • If the feeder has Plexiglas sides, most people put tape on it, or mark it (with a plaid or crosshatch design, stripes or X's) with a permanent black magic marker/black electrical tape so the birds don't try to fly in/out that way. If you are using a feeder with an entrance/exit hole on either end and Plexiglas sides, and a new visitor freaks out and can't figure out how to get out, drape a towel over the feeder so that the only light coming in is through the holes, and the stuckee will figure it out (Thanks for this idea Bluebars).
  • Hanging feeders that swing in the breeze may make some birds skittish. You can try putting it on a table or platform instead to get them used to it, but this may provide access for chipmunks etc. You can also mount it on a platform.
  • The Droll Yankee X-1 feeder with a clear globe top is nice because the birds can see mealworms or suet through the top, and it keeps things dry, but it does not effectively deter starlings, even when the top is dropped down very low.
  • Never put mealworms inside a box with an active nest in it. I also do not recommend using a nestbox as a feeder, especially if you have House Sparrows. If bluebirds are feeding in it and get trapped inside by a House Sparrow, they could be killed. Any feeder should have more than one way out.

Preventing Mealworm Escape: Live mealworms can crawl up the sides of a rough container/feeder. To avoid losses, put mealworms in a glass (e.g., small Corningware glass dessert dishes [5" diameter] or votive candle holders - you can use a glass drill bit to put in weep holes)/ceramic/steep sided plastic container (sturdy enough for perching) or cat food tin to prevent escape. If you place these on a deck or railing, be prepared to have them eaten by other birds. Also, sunlight and rain will kill the worms, and most birds won't eat them afterwMealworm or suet feeder by The Bluebird Nut.ards. Don't fill up the containers with mealworm bedding or frass, as bluebirds aren't good at picking through that stuff to get to the worms.

Supplement Calcium: Mealworms are calcium depleting, and birds a week away from fledging need to have strong bones for that first flight/crash landing. Calcium deficiency can also cause egg binding in laying birds. If you are feeding a LOT of mealworms (perhaps to help a widow/widower, or during cold rainy weather), the following is recommended (based on nutritional research on poultry and parrots) by veterinarian and bluebirder Linda Ruth. You can also put out crushed, dry chicken eggshells (in a feeder or on a patio where the birds can see it - MORE info.)

  1. Put mealworms/other insects in to a plastic bag with calcium carbonate or calcium citrate powder, and shake it gently to coat them. Both are readily available at health food stores or on the internet. Calcium carbonate is less expensive. You can also sprinkle on a small amount of avian vitamins at the same time.
  2. Add calcium to the diet of feeder insects (called "gut loading) you offer, using vitamin and mineral supplements sold in pet stores, mostly for feeding pet reptiles. They are expensive though, and have not been proven to work.
  3. Another option is to make up the following mixture which wildlife rehabbers use, and coat mealworms with it before offering them to birds (thanks Casey!) Do NOT feed just the mixture to baby birds - they could aspirate it and die.
    • 1 cup high quality kitten kibble. Wal-Mart's Maxximum or Iams is good.
      Soak in 1 cup warm water until the water is absorbed and the kibble is no longer crunchy.
    • Two hard cooked egg whites - no yolk - chopped
    • Calcium carbonate tablets plus vitamin D that will equal 1800-2000mg. calcium (probably 3 or 4). Crush tablets.
    • Combine in a blender. Final consistency similar to thin Dijon mustard.
    • Toss mealworms in it.

Assassin Bugs: Unfortunately, Assassin bugs also like mealworms. They look like a spider with a black body and big red butt. They use their "beak" to pierce and suck tissues out of prey, and "inject a very toxic, or poisonous, liquid that affects the nerves and liquefies the muscles and tissues of their prey. Assassin bugs probably have the most painful bites caused by insects." Watch out for them hiding under a feeder lid.

Recipe for Purple Martins - Egg McMeal

Bob B. feeds his martins an "Egg McMeal," especially on cold days. Mix up and heat the following (5 minutes in a microwave): 6 eggs, 1/4 cup of water, ground up egg shells. Cook only until all juice is gone. Scramble them and mix in a handful of meal worms. He says the martins love it.

Simple mealworm feeder.  Photo by Bet ZimmermanDIY Mobile Mealworm Feeder

Van Ert Design, marketed by Jenna BirdNote: After making this, I saw the "luring feeder" designed six years earlier by Floyd Van Ert, which is MUCH nicer, and has three holes and a removable top. Oh well, my husband used to think he invented the skateboard....

Total time to construct DIY feeder: 10-15 minutes. Cost: ~$3.00 (not counting hanger.) All materials should be available at any hardware store. It may not be pretty, but it's easy, cheap, and it works.

Supplies/Equipment: Hook, cable tie, 2 PVC end caps, length of PVC pipe, material for roof, mobile shepherd's crook, cat food can, Velcro, drill, doorknob cutter/Forschner bit.

Step by Step Instructions:

  1. Cut a 7 or 8" length of 4" diameter PVC used for thin wall drain or sewer pipe (I used leftover pipe from predator guards.) Might be best if it's shorter so birds can hang on the outside/don't have to drop down so far to feed - just make sure holes are still exposed after putting caps on.
  2. Put PVC end caps on either end.
  3. Drill two entrance holes (opposite each other) in the middle, using a Forschner 1.5" bit or a doorknob cutter. Smooth edges with a file if necessary.
  4. Add a roof (plastic bucket top, frisbee, pretzel can top painted white to reflect heat, piece of plywood, whatever - big enough so it will shred rain away from interior). Screw roof onto feeder with hook (through top of PVC cap and roof. Pre-drill hole if needed.)
  5. Put a cat food can on top (secure with Velcro or a magnet so it can be removed for cleaning), drilling tiny holes in the bottom for drainage. Bluebirds seem to prefer to eat from the top, and a full can also lets them know the feeder has been filled.
  6. Use a cable tie to hang the feeder on a shepherd's crook that can be moved around as needed.

Note: This feeder on a crook will not keep squirrels out if you use it for suet - use a squirrel-proof predator guard on the hanger if you plan to feed anything with peanuts/peanut butter in it. Depending on the size of the hole, larger birds can get inside/stick their heads in to feed. Also see info above on making a homemade, squirrel and starling proof cage feeder. Also see Fawzi Emad's design.

More info on feeding bluebirds:

Bluebird feeder links: links to instructions for making your own. Many can also be used for suet.


Because the bluebird is beautiful and readily accepts the help of humans, and, because people love to nurture beautiful animals, especially those that are endearing, a strong natural bond is forged between man and the bluebird at the nest box. In many cases, that relationship not only lasts a lifetime but also grows into a greater awareness of the plight of all wild animals and the plant kingdom on which all animals depend.
- Gary Springer, 2005

HOME | Basics | Resources | House Sparrows | House Wrens | Nest/Egg ID | Site Map and Search | Suet Recipes | Tree Swallows | Contact me Bluebird Conservation

May all your blues be birds!

If you experience problems with the website/find broken links/have suggestions/corrections, please contact me!
The purpose of this site is to share information with anyone interested in bluebird conservation.
Feel free to link to it (preferred as I update content regularly), or use text from it for personal or educational purposes, with a link back to http://www.sialis.org or a citation for the author.
No permission is granted for commercial use.
Appearance of automatically generated Google or other ads on this site does not constitute endorsement of any of those services or products!

Photo in header by Wendell Long.
© Original photographs are copyrighted, and may not be used without the express permission of the photographer. Please honor their copyright protection.
See disclaimer, necessitated by today's sadly litigious world.
Last updated November 12, 2013. Design by Chimalis.

Chimalis