Flame, our hummingbird feeders were covered in ants, and we've had good luck using Tanglefoot on our hummingbird feeder poles. Not only would the ants not cross the tanglefoot, the trail of ants to the poles stopped also. Maybe that'll work on the feeder legs, and help keep the biting ants away since they can't get to the fish food for an easy meal.
Tanglefoot's sticky stuff. Be sure and wear gloves, and use your least favorite butter knife to spread it.
