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Monday, August 1, 2011

How To Start A Mealworm Colony

Today's post shows you how to very simply start a mealworm colony. Mine will be used to feed my rambunctious little hedgehog. You know you love your pets when you're willing to gross yourself out doing little things like this to keep them fed.
To start a meal worm colony, you will need the following supplies:
  1. Plastic container with secure lid
  2. Hole puncher or other device to put holes in the lid
  3. Oatmeal Oats
  4. Slice of carrot or apple
  5. Live mealworms (I'm starting with 150. This cost about $5.)
First, prepare the lid of your container by punching small holes into it. I used the smallest hole punch setting on my scrap-booking hole puncher thingamajiggy.

You don't want holes that are too large. This will keep other annoying bugs and pets from entering the container, or sneaky little mealworms and beetles from escaping.

Tip:  Punch as many holes as you possibly can.  The more airflow you have, the less chance of grain mites thriving in your oatmeal.  You may also consider using a mesh top instead.
Next, add your live mealworms. I won't lie, they look pretty gross like this.
To save yourself from puking, quickly add oatmeal to cover them up. Add enough that they are completely covered. Your meal worms will be eating this oatmeal to become fat and delicious for your pet. The oatmeal also adds some fiber to your pet's diet :)
Then add one slice of carrot to the top of the oatmeal. You can also use apple, but carrot doesn't go moldy as fast. This provides the nutrients and water that your mealworms will need to stay alive. You must change out the carrot once per week so that it stays fresh.

Try to minimize how much water content you are adding to the container. Otherwise, it will get moldy in there!
Now seal your container with a lid! Make sure that the lid is secure, but has LOTS of airflow.
As you stare at the oatmeal, it will start to move. Then mealworms will start to burrow their way to the surface. It's really quite fascinating, but I know it will seriously gross out other people.
Now your mealworm colony is ready to begin!

(Note: See how much fatter and "tastier" this mealworm looks compared to the earlier pictures? This is a mealworm that has been well-fed for the past 3 days since coming home from the pet store where they were kept in the fridge. My hedgehog wouldn't even touch them after they came home from the pet store, but 3 days later, he was VERY interested in them.)

Each week, you will need to change out the piece of carrot for a fresh one. The regular mealworms will eat the oatmeal and carrot and grow.
Over time, they will start to change.

The first sign of this is shedding of the skin to grow bigger.

Then they will shed to become a very different looking thing that is commonly referred to as an alien.
Here's a close up of a particularly large one. You can see how big this one is compared to the other mealworms.

The alien will start off light coloured, and become darker in colour. Eventually, they will become beetles (Darkling beetles).

These beetles mate, lay eggs, and the eggs hatch into tiny mealworms that grow into big mealworms.
To increase how nutritious, fat, and juicy these mealworms are for your hedgehog or other pet, you can add things for your mealworms to eat. Mine are fed 2 pieces of cat kibble to give them more protein. The cat food also makes the mealworms smell (and probably taste) a little more like his regular food. You can also add a piece of cuttlebone to add calcium.

You can read more about starting your own mealworm colony here:

This is a pretty good video on how to start a mealworm colony:

Good luck with starting your own mealworm colony!


08-10-2011: I found that a lot of my mealworms were dying or dead. On closer inspection, I discovered that the oatmeal was somewhat moist and that some of the dead or dying mealworms seemed to have something that looks like mold or mildew on them. I think I added too many carrot slices last time (three).

I used a wimpy plastic fork to take out all of the healthy mealworms and aliens and put them into a different container. Then I washed out the old container, put in fresh oatmeal, put the mealworms and aliens back, and added ONE slice of carrot. I threw away all of the dead mealworms and the tainted oatmeal and carrots.

18-11-2011: I discovered two beetles!

They are mostly white in colour so they must be brand new. Also, I looked closely at a mealworm that looks dead and found that it's not dead.

It's just shedding or something, but hasn't popped out yet. Ooops! I think maybe some of the dead mealworms I threw out yesterday weren't really dead. Sorry, mealworms!

I am happy to have two beetles now. I read somewhere that you need about 5-6 beetles to have a sustainable colony. I have lots of other aliens so I'm pretty confident I'll reach 5-6 beetles in no time now! I just have to be careful not to give them too much carrots.

As a side note, I think Slimey the Worm from Sesame Street is a mealworm. He has the same orange stripes... hm...

08-13-2011: I have noticed at least 5 beetles now. The mealworm colony is in good shape for becoming self-sufficient.

The white beetles from yesterday are also turning dark brown now. You can see a white beetle beside a dark brown one in this photo.

The composition of my mealworm colony is beginning to change. I have proportionately more larvae, pupae, and beetles than worms.
Many of the beetles are now black too, and you can see from this image that there are quite a few of them. In this image alone there are six of them.
This has resulted in some unfavorable side effects. If I let a carrot go slightly dry, the black beetles will start eating the larvae in order to obtain water content.

To minimize loss, I have now separated the adult beetles into a separate container. Any new mealworms that they produce will be moved into the mealworm container.


There are only 2 regular mealworms left.  The rest of the mealworms have either been consumed by my hedgehog or have turned into beetles.  The beetle container is quite full.
I looked at the particles at the bottom of the beetle container today and found a couple very tiny almost see-through worms.
These will grow up to become new mealworms.  You will see the movement of the baby mealworms more than the actual mealworms themselves when they are this small.  They should grow fast though.


There are now quite a few baby mealworms. I have been using the beetle container like a salt shaker to put the tiny worms and eggs into the baby container. It works great!  
The worms are still super tiny though.  You can see their size compared to the flakes of oatmeal in the photo. Poggles will have to wait a very long time before he can eat mealworms again at this rate.  
It has been about 2 months since I started the mealworm colony.  This is a much slower process than I thought!


I have been able to harvest about one mealworm per 1-2 days since December.  That means that it took over four months for the mealworm colony to be ready.  That's slooooow.  Oh well, the good news is that it IS productive and that Poggles has regular, fresh mealworms to eat.  I think that's a good thing.


My mealworm colony numbers were too low so I went to the pet store and bought a new batch of 200 worms.  The upside is that Poggles has new mealworms to eat.  The downside is that I seem to have gotten grain mites.  They look like little moving specks of flour and they coat the carrots and other things I put in.  Ugh...

So now I have to dispose of all the infected oatmeal bedding, wash any worms present, and use new oatmeal bedding.  I will microwave the new bedding ahead of time so that I kill any mites present.  It's a pretty gross thought that there might be grain mites in the oatmeal that I buy from the store.  Yuck!


Poggles has been eating 2-4 mealworms per day and there are tons of new mealworms to replace them each day.  I discovered that the key to having a better producing colony is MORE ADULT BEETLES.  At first I was feeding both worms and beetles to Poggles, but now I never feed any of the live beetles to Poggles. (But if a beetle looks like it just died, I'll let him have that.  I check the containers every day.)

I have at least 20 adult beetles now in one small container (which I still use like a salt shaker to put eggs and baby worms into the the big baby container).  I also have a third small container which is specifically for aliens.  Every few days, I'll pick out one extra fat mealworm and put it into the alien container.  These are my future adult beetles so that I will always have new beetles on a regular basis.

The grain mite problem is now very minimal.  I punched lots of extra holes in all the containers and use only one small piece of carrot per container.  I also dump out the frass every few months.  This is easy for the alien container, but the baby container is very hard since I have to watch out for the tiny baby worms.  I think I need to use a finer sieve for next time.


Totally Timmy said...

a little to yechy even for said...

Lol, well, I figure whether I have a self-sufficient mealworm colony or not, it would be good to keep them fresh and alive until they are all eaten. Plus this tricks my hedgehog into eating more fiber!

PatchworkPottery said...

EWWW! You must REALLY love that little guy!!! said...

Yes, the things I go through for this little guy... :)

Jenny said...

wow...I have to say it are so so brave Marie! The pictures kinda gross me out until the one that showed how the "alien" turned into a beetle. I thought that was pretty cool. Thanks for posting up the pics...very educational indeed :D

Jenny :0)

Anonymous said...

The reason you keep having issues with mould and mites is not the amount of carrots that are being used but simply not enough ventilation.
I found the same problem and had to do the disinfecting of the tub, removing the worms, destroying the oats substrate etc.

I solved this issue by instead of using holes in a lid i cut out the central section of the lid and stuck it in a pair of tights.

This gives more ventilation and less chance for mould to develope

Nicky's Toy Box said...

You don't need to add a "water source", it just causes your oatmeal to become mouldy and damp, which attract the mites as well and make their eggs hatch. I have a very sufficient colony that supplies my 4 bearded dragons and 3 leopard geckos with about 10-15 worms each per day. said...

Hi Monique,

I think maybe your air is more humid than mine then. I find that when I let the carrot dry up, beetles start to die and the mealworms start to look less plump. They look kind of shrunken! I wish I could leave out the water source too like you!

Anonymous said...

I am looking to feed the wild birds come winter and heard about having a mealworm colony but I am worried about the beetles climbing out. my information says to keep them at room temperature but I can't have beetles running all over. at what point would be best to remove the worms to give the birds said...

Hi Anonymous,

The beetles don't climb out of my container. As long as you have a lid or mesh on your container, you will not have beetles all over the place.

You can remove the worms to give to the birds any time that they are big enough to use, but you need to make sure that you always allow a certain number of worms to remain alive in your colony so that they can become the next generation of beetles.

Good luck!

Anonymous said...

OK, well I am feeding meal worms to a Gecko that lives in my garage. This isn't a pet Gecko, just a cute little Gecko that hangs out and feeds on insects in my garage. He was looking skinny so I purchased some mealworms and now after reading your page I hope to be able to harvest my own mealworms!

Thank you for the info!

Anonymous said...

Really helpful, thanks!

Anonymous said...

I'm hoping to have a leopard gecko soon, am I'm getting my fill on research for everything. This was probably the most helpful post I've seen yet. Thank you so much said...

Hi Anonymous,

Thanks for your comment. I'm glad you liked this post and found it helpful.

Unknown said...

Excellent! I thought I was doing something wrong, as this process is taking quite a while. After about two months, I have one adult beetle and about 20-25 aliens. They’ve been separated from the worms. I give them all a fresh apple core every time I cut apples for my kids, as well as a few orange cubes (Fluker’s) to up their nutritional value/health. Thank you for the great information and VERY detailed photos!

Unknown said...

How do you kill the beetles of them because they are in my house it's my next door neighbour that keeps chicken's an now I have them in my house so please can you tell me how to kill them and get rid of them ASAP thanks to anybody who can help me