you could even do flies over the sink, just fill it with a little water so the flies that escape during the transfer land in it. Flies really aint that bad, i'd rather deal with flies than crickets really, and flies are super cheap to culture

my leucs are becomming bolder each day. One of them is always out hunting during the day. Sometimes they hunt together but i mostly see one at a time. I like watching them hunt, they give a stare down to the fly for a bit then SMACK, fly gone