Pinhead crickets are about the size of fruit flies or maybe a little smaller. The problem with pinheads is they generally stay down at the bottom hiding. The flies willl crawl to the top where your mantis spends most of his time. You shouldn't have flies in your house. Get the flightless fruit flies. If some do escape they soon die and they can't fly. I have tons of crickets ranging from pinheads to adults. I feed them mixed green leafy veggies, cat food, tomatoes, fruit, fish food etc etc. The flies stay in little vials that I get from www.carolina.com They eat the mixture that goes in the vials. I also get that from carolina.com It is mixed with water and yeast and there is about an inch of it in each vial. The flies are really easy once you get them established.
