We note that seven feeder contains a 3-letter animal whose names start with letters from A-G. Taking these feeders and sorting by animal name, they are
CHAPE
HELLOBEETIFUL
JUDICATORY
JACKALDOGHYBRID
HEELBALL
FLYINGACE
MARGARITA
Taking the number of bars on each cage as an index, we get
CHAPE
HELLOBEETIFUL
JUDICATORY
JACKALDOGHYBRID
HEELBALL
FLYINGACE
MARGARITA
This gives our answer, COOLANT (get it. ant. like the bugs)