i noticed my guys LOVE when things wriggle. so maybe just cut up the worms and leave them in the tank? i feed them around my dinner time, a few will eat but most eat after i go to bed. maybe grab a cpl guppies from the store? i had asked steve this question previously, you can keep them for a while just make sure you give them enough time before it gets to cold to look for a spot to brmate and find food