+1 They may be stressing out. Put only a few in and once those get snatched, add a few more. I've noticed that even after they catch something they'll drop it and take off if bothered by another ff or a frantic sibling.
I say let 'em starve then. It is sometimes annoying. You can give a mantid a bug, but you can't make them eat. I guess you know there isn't a molt coming on to make them do it. :lol:
How many have you lost? As long as there are some eating and gaining strength you should be ok. Maybe they just have decided the captive life isn't for them. "Good-bye cruel world"
make sure they get a really warm misting twice a day, new babies must have water, if to many flies open their container and let them jump out, you can catch any babies with a skewer or pencil, the babies wont go far, dont worry about them running away.
I just read what everybody wrote. They are doing well. It is cold now. D. melanogaster fruit flies are about 2mm long. Lots of people just guess how big the mantids and other insects they have!