Recently purchased a corn from PetSmart, had him for about a month, and suddenly I noticed 20-30 fruit flies in his terrarium. The terrarium has aspen bedding, one of the PetSmart water dished, and a hide and climbing branch, both built out of kiln-dried white oak lumber from the woodshop where I work. Is this maybe a maintenance issue? I changed out his substrate a few days ago and there are still a few flies hanging around. Advice? Comments?