In addition to posing a health hazard to the bird, the tiny parasites actually eat the feathers. Naturalists have noticed that birds with damaged bills cannot preen themselves properly and, as a result, harbor many more feather parasites than do normal birds.
Dabas pētnieki ir novērojuši, ka putniem, kuriem ir traumēts knābis, ir grūti sevi apkopt un tāpēc tiem parasti ir daudz vairāk spalvu parazītu nekā veseliem īpatņiem.