Make your own
The Ideal High Protein "Live Food" for your Birds
How to Breed and Feed Mealworms






Showing Mealworms & Pupae

Showing Mealworm & Pupae

Mealworm Life Cycle
How long?
Other information
Egg 714 days      
Larva 3090 days Bran/oatmeal/chick mash Apple/carrot/lettuce/Fruit/Veg 5 moults occur
Pupa 1020 days      
Adult 510 days Bran/oatmeal/chick mash Apple/carrot/lettuce/Fruit/Veg Death: 30 days
Egg The cycle continues.
Life cycle of the Mealworm

They go through four distinct stages during their life cycle.

  • A female beetle lays as many as 500 Eggs in her brief lifetime of a month or two.
  • The eggs are about the size of the full-stop at the end of this sentence.
  • After a couple of weeks the equally tiny larvae emerge from the eggs.
  • The larvae are known as Mealworms - altho they are not true worms.
  • The larvae seem to have two purposes in life:                                                           
    • To eat and grow
  • Any similarity to a true worm is incidental
  • Mealworm larvae are golden yellow and have 13 segments                                                                                                                             Beetles at all stages + Pupa
    • a head, three thoracic segments, and nine abdominal segments                           Beetles start off pale>brown>Black
  • Mealworm larvae are the counterpart of the Butterfly Caterpillar.
  • They pull themselves around on six stubby legs
    • one pair on each thoracic segment.
  • Mealworms are the larval stage of Darkling (Tenebrio) Beetles. 
  • Beetles, along with other insects, are members of the phylum "Arthropoda",
    • a word meaning "jointed legs".
  • Like all members of their phylum, they have their skeleton on the outside, like a suit of armour.
  • This is practical when they are under attack but very inconvenient when they are trying to grow.
  • Arthropods solved this problem by moulting (shedding) this outer shell-like cuticle periodically.
  • Immediately following the moult, the soft white larva expands before the new larger cuticle hardens.
  • For mealworms this process repeats five times over a 2-month period
    • after which the larva is about 3 cm (just over 1") long.
  • The final larval moult reveals the next stage  -  the PUPA.
    • these are the "Soft white, caterpillar-looking things"
      • You can see them in the pictures at the top of the page
      • Click on the Pictures to enlarge them and see the Mealworms and Pupae more clearly.
  • Pupae don't eat and they don't move except for a twitch when disturbed.
  • Inside, however, the mealworm is turning into a Beetle
    • much the same as a caterpillar turns into a butterfly while sequestered inside its chrysalis.
  • In 2 - 3 weeks the Pupa splits open and out walks a beetle,
    • It's white at first but soon turns brown and finally black, after a day.
  • The Beetles mate and lay eggs, and the cycle repeats itself.


  •  Mealworms and Darkling Beetles are rarely seen in the wild
  • They are most often found in barns, grain storage facilities and food preparation areas.
  • Mealworms and Darkling Beetles are small but not tiny
    • They don't bite, smell, fly or jump and they are extremely easy to care for.


  • You can keep & breed Mealworms in a  large, relatively flat container with their food source
    • An ideal start number is approx 1000 mealworms,
    • obviously less, if you start with the Beetles, as they can lay up to 500 eggs each
      • Male & Female Beetles MUST be present
      • In the picture below I am using a deeper smaller tub, as I only had about a hundred Mealworms to start with.
  • This will provide a constant source of "Live Food" thru the winter months and into the Spring
    • and into the start of your Breeding Season, when you need to up the Protein levels for your Birds
      to bring them into Breeding condition.
      • Mealworms are a good, High Protein "Live Food" for your Birds

Ideal foods Sources are :

  • Wheat Bran, Oat-Bran, Rolled Oats, Breakfast Flakes/Muesli (If NO sugar or salt added) or chick starter mash
  • The food must be kept dry otherwise it can go mouldy.
  • You've heard the saying, "you are what you eat" well this applies to the mealworms when you use them to feed to your birds.
    • What you have fed them decides how nutritious they will be for your birds!
      • This also applies to the fruit/veg you use as your "Water Source"
      • as well as the substrate you use as their basic "Food Source".
  • Mealworms can go through their complete life cycle without any added water
    •  They are very efficient at extracting water from the fruit/veg you add.
    •  It is recommended that small bits of apple, potato, carrot, lettuce, Banana etc., be added from time to time as their  "Water Source".
    •  Remember to remove all stale fruit/veg. b4 it goes mouldy and b4 you add new.
  • They seem to thrive best when the colony of Mealworms has a large surface area.
  • Keep the bran or the food source you have decided to use
    •  about 2 or 3 cm (1") deep in a basin, Cat-Litter Tray, aquarium, or plastic shoe box etc.
  • If the container sides are steep and smooth, it is not necessary to keep the container covered.
    • I use an orange mesh 10kg carrot bag doubled over
      •   this keeps the container covered but allows plenty of air - essential
    • Mealworms can't climb the shiny plastic sides of a container, so won't escape

           Click on Picture to enlarge > >    

  • Adults and larvae seem to prefer hiding under bits of paper or light cardboard
    • I use cardboard egg boxes which is ideal as it is undulating and provides shaded areas
  •  The Pupae give no indication that they care either way - they are in a kind of "Limbo"

The mealworm's preferred environment

  • Is very dry, moderately warm and dark.
  • A bit of apple or other fruit/veg provides extra moisture for the mealworms and seems to stimulate rapid growth.
  • Keeping the container on the top of a wardrobe in a warm room seems and ideal environment.
  • As the temperature increases, so does the rate at which mealworms advance through their life cycle.
  • Under ideal conditions, the complete life cycle can take place in as little as 3 months
    • but more likely it will take 4 months.
    • Cold slows the process almost to the point of suspended animation.
    • Mealworms can be put into the refrigerator (not the freezer) for periods of time to stop metamorphosis.
      • or if you are storing them to feed to your birds and don't want them to continue with their life cycle.



  • Most people start out with Mealworms and go thru all the stages up to eggs being laid and hatching
    • Others buy them in as Beetles - to cut out a lot of waiting
  • Keep them in the Bran or Oatmeal with a piece of Fruit/veg as their water source.
  • Then when they've grown sufficiently and moulted out of their skins for the final time
    • (they moult approx. 5 times as they grow out of their skins and shed them)
      • You will see the shed skins like those of a snake, littered in the Food source.
    • They then turn into the soft white pupa
    • They stay as fairly immobile Pupa for 10 - 20 days
  • At this point a lot of people remove the Pupa into a separate container with similar Food source in the bottom
  • They then hatch out into "Darkling Beetles"
    • They are Pale coloured when they first hatch but soon darken up into Black
  •  Remove these Beetles and keep them in a separate container.
    • Use the same Food and water source as for the Mealworms
    • They can fly but tend not to so keep the container covered with something they cannot
      penetrate but still allows air to circulate freely.
  • The Beetles will lay their eggs 5 - 10 days after they have morphed into Beetles
    • You will not see the eggs as they are minute - as small as a full stop.
  • Eggs Hatch 7 - 14 days after they have been laid
    • You will not see the small mealworms until they have grown up to about 1/8 - 1/4"
      • Smaller Finches consider them a delicacy when they are young and soft at this stage/size of their growth.
  • So, basically they are removed into separate containers at each stage of their development.

If you order Mealworms, Beetles/Pupa thru the Post to use in a Breeding Programme

  • What to do when they arrive.
  • Mealworms &/or Beetles are usually Posted out in a container with a "breathing" cap to provide air.
  • Keep the Beetles in a Warm room/area in low light.
  • At warmer room temperatures, larvae will soon pupate.
  • Cover Beetles loosely with a paper towel to provide crawling space.
  • Beetles can fly but rarely seem to
    • a paper towel should keep them enclosed where you want them.
    • or mesh Carrot bag if they are in the mealworm/pupa stage.
    • THEY MUST HAVE plenty of AIR CIRCULATING or they MAY DIE !
  • Add slices of potato or carrot etc (see above) for moisture and add a substrate of bran/oats etc. for food.
    • Replace as necessary or if it becomes mouldy.

If you Order Mealworms to Feed to your Birds, thru the Post

  • Keep them in a cool environment i.e. Fridge (not for human use preferably!!)
  • They need no special care but should be used as soon as possible, as they have a rather short life span.
  • Store in a cool place at 45 to 65 F out of direct sunlight.
  • Keeping them cool slows development, so they do not metamorphosise into Pupae
  • Keep them in a feed medium (see above) Bran etc.,
    • this keeps them healthy and nourished until you are ready to feed them to your Birds.
    • Don't forget to add a small piece of Fruit/veg as their water source

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:  Maggots are also interesting 
  • Feeding them can be done in a number of ways :
  1. Fresh Maggots - put them into bran or sawdust until the black line down their bodies disappears (usually a couple of days) you can then feed then in the same way as mealworm
  2. Let them form a chrysalis - then feed them direct
  3.  Some people then put the chrysalis into a box with small holes in the top and as the flies hatch the birds get used to catching them -but not all birds eat flies
  4. "Pinkies" are acceptable but many birds don't seem to eat Pink things -
    • there's research going on about colour of feed at Glasgow university at the moment for which I've supplied the birds - there wont be any results on that for a couple of years
  5. Usual cheapest place for mealworm is Priory Pets in Cage Birds Mag
    • - they will happily keep somewhere cool for up to 6 weeks
    • so buying in bulk is possible-
    • if you do this have to keep them in trays so that you can constantly add dry food otherwise they sweat and die.
  6. Alternatively look on Nettles, Beans, Cabbages, Roses etc., for Aphids, Caterpillars etc.,
    •  just nip the infested shoots off and feed in a dish to the birds

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