butter worms are great feeders provided that your cham like them (my chameleon just look at them and shrug them off).
They do smell wonderful.
They are great nutritionally and high in calcium.
best to refrigerate them and take them out when you want to feed them to your cham.
They only eat trevo wood and that plant exist only in south America.
The Butterworms came here radiated so they will not carry any diseases or parasites to US. Because of that, they become sterile. It's impossible to breed them.