sentences:  The avian lice prefer to feed on white tail spots, and they are generally found more numerously on short-tailed males, indicating the function of unbroken white tail spots as a measure of quality.In Texas, the swallow bug ("Oeciacus vicarius"), which is common on species such as the cliff swallow, is also known to infest barn swallows.Predatory bats such as the greater false vampire bat are known to prey on barn swallows.