The study found that the fur used by birds to line their nests contained insecticides from pet flea treatments, such as fipronil. The researchers collected 103 nests from blue and great tits ...

The eggs are laid in the host nest, where the larvae develop as scavengers, feeding on detritus and flea faeces. The resulting pupae can remain dormant for some time, emerging as adults in response to ...

Both of these are harmful insecticides used widely in flea and tick treatments for pets, which then end up in birds' nests through pet hair lining. The researchers also tested all the nests for ...