In areas where fire ant populations are very high, the ants may reduce populations of other ground-dwelling insects, including native ant species, with which they compete. They also may attack the nestlings of ground-nesting birds and perhaps other wildlife, although impacts on wildlife populations are poorly documented. Fire ants have even been known to climb trees and enter bird nests. One possible indirect harmful effect of fire ants on the environment is overuse of insecticides in attempts to control their populations. See also FAQ #814: "Imported fire ants are killing wildlife such as quail, deer, lizards, songbirds and horned toads. Why isn't anything being done?" On the other hand, imported fire ants are good predators and have been shown to reduce ticks in pastures and to control insect pests, particularly caterpillars, in crops such as sugar cane and cotton.