Wasps such as yellowjackets, bees and ants can be common nuisance pests at hummingbird feeders (sugar solution dispensers). While these scavenger insects may have little impact on hummingbirds, they do occasionally interfere with the bird-watcher's enjoyment of the backyard feeder. In addition, ants often climb inside a hummingbird feeder and drown creating an unsightly mess that necessitates frequent cleaning and replacement of the solution.
Tolerating insects at a bird feeder may be the most practical and efficient solution to this perceived "problem." Alternative solutions are described below.
"Bee guards" are available for most current hummingbird feeders and can be purchased at bird feeder retail outlets. Bee guards are small red or yellow perforated plastic caps that fit over or into each feeding tube like a grate. Hummingbirds are able to feed from grated feeders by reaching their slender beaks through the square holes of the grate to the solution deeper within. Insect mouth parts are generally too short to reach the solution. Bee guards do help keep bees away to some extent. However, wasps are not so easily discouraged and may persist in trying to feed on the sugar water.
Wasps and the hummingbirds occasionally "argue" over feeder tubes. Fortunately the "hummers" are persistent and usually manage to find a spot with no wasps.
Several "barriers" have been suggested to keep ants from climbing onto hummingbird feeders and eating the sugar water and/or drowning in the bottle. If the feeder is hanging from a metal pole you might discourage ants (as well as chipmunks, squirrels, and raccoons) by "painting" the feeder pole with Tangle-foot or Tack-Trap , extremely sticky grease products used to coat the inside of insects traps. Presumably, you can use cooking oil on the pole but it must be reapplied frequently. Another suggestion is to suspend the feeder on a short length of monofilament line (fishing line) and then coat just the string with vegetable oil. Some feeders come with a small oil reservoir ("ant moat") built into the suspension wire. A homemade ant moat could be fashioned from a plastic jar lid and wire or line.
This article originally appeared in the July 28, 2000 issue, p. 97.