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Large amount of mold in mealworm container


New Member
3 Year Member
Hi all,
If there is another post about this then I apologize, but I looked around and couldn't find anything that would really help me. So a week or two ago I put a couple baby carrots in with my mealworms. They're just in the default container, plastic one about 5 inches in diameter, from Petco. I was stupid and didn't consider the possibility of the carrots molding, so I was quite surprised when I opened the lid today. The oat-like stuff that they come in was covered in mold, and there was a huge chunk of the moldy carrots throughout the entire container. Super nasty. I chucked out the moldy oat-like stuff and cleaned the container and filled it with new steelcut oats, no carrots. Will I still be able to feed the worms to my T? If not, then that's okay and I will get new ones (lesson learned), but would love to keep the ones I got.

One more thing, the mealworms grew A LOT ever since I put the carrots in and that maybe is a good sign that they're healthy and all, but I worry about them turning into beetles. I got a tarantula to conquer my arachnophobia (it worked!), but other bugs still give me the heebie jeebies. I am nervously awaiting the day I open the container to see a huge darkling beetle. Eek. Anyway, the mealworms are freaking huge and I have a feeling they might change soon. I'm wondering a) is there any way to maybe... slow down the process? b) can tarantulas eat darkling beetles? c) there is a substantial amount of worms, so is the container big enough? (It's about 5' in diameter and about 3' deep)

Hopefully someone can help me out :) thanks so much


Active Member
3 Year Member
New York
Should still be fine, I went through the same thing when I first got mealworms, feeders from what I've experienced will still eat parts of the food that doesn't have mold or avoid it entirely.

Dave Jay

Well-Known Member
1,000+ Post Club
3 Year Member
Mt Barker South Australia
If they were smaller I'd say to feed them after they've shed their skins but I guess they're ready to pupate by the sounds of it. Mould is better than when you get the ammonia smell (cat pee smell) but you're bound to add mould spores along with the worms , whether that's a problem depends on ventilation, which was your main problem with the worms themselves. The worms will pupate early when food runs out so I see four choices.
Separate them into several containers with a layer of rolled oats on the bottom and feed them small slices of carrot and hope they keep growing and shed.
Put them in a tub of rolled oats and put them in the fridge and make sure you pick out any dark ones ,they are dead or dying, they won't moult or pupate in the fridge, eventually they'll all just die.
Set up a critter keeper (or a tub with lots of ventilation) with oats and egg carton and start a colony and never buy mealworms again once it's established.
Freeze some and thaw and cut them up for slings when needed (if applicable).

I think you'll find that the beetles aren't as scary as you think, they're very sedate, bumbling little beetles really, to me the worms are "creepier" , especially holding a few in a closed hand, but we are all different.
I think mealworms are the best feeder colony you can keep if they suit your needs, next to no maintenence, no offensive smell , no noise and no extra heat required in most cases. Cheap to keep too, a bag/box of rolled oats a couple of times a year, a carrot a week and veggie scraps, laughin'! :)


New Member
Research is obtainable and knowledge is power...

The study about plastic was done by Stanford University.

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