The common waxbill's habit of adorning its nests with fur plucked from carnivore scat turns out to discourage attacks from predators.
In southern Africa, these songbirds build enclosed grass nests on the ground, explains Justin G. Schuetz of Cornell University. The birds share their habitat with a goodly number of rodents and snakes that hunt for eggs.
Schuetz knew from old descriptions that the birds follow the unusual practice of pecking at scat left by servals and other carnivores. The waxbills then bring home lumps of excreted fur to tuck into the walls of their nests. "I could find some of the nests just by sniffing," says Schuetz.