Another excellent question!
Let me share a part of a message I just sent a friend:
”From my experiences, you can put any number of ghosts together, given a few things. First of all, room is a pretty important factor. If you have a decent sized enclosure, you can fit quite a few ghosts together, but there mist be lots of branches for them to hide on. They don’t move around a whole lot, but they like to be “communally secluded”, if that makes any sense. Also, they must be well fed. I don’t think anything else needs to be said here. Just make sure they’re always full, and they won’t eat each other. The last really important thing is, once they’re maybe L4 or L5, I would split up the males and females. Females grow a bit larger, and they’ll eat the males from time to time. This last thing isn’t quite as imperative, but it’s usually much safer, as you don’t want to run out of males!”
To answer your question specifically, with my mantids, I just take my fly culture, put a specially made “dispenser” lid on it, and shake a bunch into the enclosure. As I’ve said before, I use jars for cultures, and the special lid is a water bottle top that I’ve glued to a jar lid. I’ll post a picture when I get home. Anyway, it makes it really easy to dispense anywhere from 1-100 flies into the enclosure. Honestly, the mantids are very good at finding food for themselves, so I just dump at least 2 flies for every 1 mantis. But it doesn’t have to be perfectly exact. Just make sure there is at least 1-2 flies per mantis, and you’ll be good.
Next question, if a mantis is not eating. If there’s one that isn’t eating, you could tell by the size of the abdomen. If it’s abdomen is small/flat, it is either too slow to get the food, or not strong enough to (meaning it might die). Whenever I see this, I take it out, and house it by itself until it shows improvement. Usually it will be fine if you’re able to get it to molt.
Next up, having food in the enclosure always. Not a bad idea, if it possible, but only if you aren’t expecting any molts soon. The flies, if always kept in the enclosure, can disturb the mantis mid-molt, and cause it to fall. Also, if you do keep a constant supply of food, make sure that there isn’t too many flies, as they can cause stress with the mantis.
Last question, about molting. As long as they’re well fed, you shouldn’t have any issues with them. I’ve only ever lost one mantis to a “attack of opportunity” (L1 eating a sibling molting to L2), but it was only because I didn’t dispense any flies for 3 days, because molting was taking place. But you should have nothing really to worry about.
If you need any other help with other questions, and the other amazing forum members don’t answer them, feel free to reach out to me!