and, birds know it and use the fiber in their nests.
Bad Butts Good Except
“The butts cause [genetic] damage to finches by interfering with cell division, which we assessed by looking at their red blood cells."
“I think the anti-parasite effects the cigarette butts provide must outweigh any negative problems they cause,” says Portugal. “Alternatively, the genotoxic effects take longer to manifest, and the adult birds aren’t aware of any problem.”