Small 10 gallon desktop aquarium with cherry shrimp, 1 remaining pygmy cory, 3 pygmy hatchets, and 5 chili rasboras all cohabitating nicely for the past 6 months. Occasional predation of shrimp babies, presumably by hatchets but steady shrimp population is slowly growing. Yesterday added*rabbit snail, 5 additional pygmy cories, and 6 green rasboras and have had 2 decapitated moderate sized shrimp in the last 12 hours. The remainder of the bodies were intact. I haven't seen the rasboras leave the main water column and shrimp have been free swimming past without any signs of the fish nipping at them. One of the cories was feeding on the decapitated shrimp after I first noticed it (not the initial kill) and the most recent body was tucked in a back corner behind rocks where it seems like the rasboras wouldn't go, but where there was recently a snail and a cory. Best bet on the killer to remove to another tank? Seems like it would be the rasboras, but location of the bodies at the crime scene doesn't really match...