mites ???

[coldinnh]

I have a similar ? since my girls have access to the outside (free range I guess) can a passing wild bird leave a few mites or lice for them to pick up?

 

[peaceful]

Yes, wild birds can spread mites or lice to chickens. That said, it doesn't mean they will necessarily. Our chickens seem fine over three years. One preventative thing you can do is put wood ashes (eg. from woodstove) in the yard for them to dust bathe in.