could have been a blue bottle fly. blue bottle, green bottle, & house flies are also known as filth flies. in the wild, filth flies visit some pretty nasty dead stuff, so i would be careful about feeding wc filth flies. some of the commercially harvested ones are grown on some pretty nasty stuff as well. all three make great feeders, but i stick to ones that you raise yourself or ones from a commercial supplier that intends them as reptile food. flies are a great feeder to raise, they can be great for eliminating boredom or snaping a cham out of a hunger strike. they are moderately easy to raise and you get a high yield in a short time. they are easy to store and keep once you get the hang of it.