Yeah, check before treating.
You've got to get way down to the skin, it's not easy.
Around vent is most likely place to find them.
Best done well after dark with a strong flashlight/headlight, easier to 'catch' bird and also to check for the mites that live in structure and only come out at night to feed off roosting birds.
Wipe a white paper towel along the underside of roost to look for red smears(smashed well fed mites).
Part the feathers right down to the skin around vent, head/neck and under wings.
Google images of lice/mites and their eggs before the inspection so you'll know what you're looking for.
If you do find some...check out this thread:
http://www.backyardchickens.com/t/1134783/permethrin-spray
You've got to get way down to the skin, it's not easy.
Around vent is most likely place to find them.
Best done well after dark with a strong flashlight/headlight, easier to 'catch' bird and also to check for the mites that live in structure and only come out at night to feed off roosting birds.
Wipe a white paper towel along the underside of roost to look for red smears(smashed well fed mites).
Part the feathers right down to the skin around vent, head/neck and under wings.
Google images of lice/mites and their eggs before the inspection so you'll know what you're looking for.
If you do find some...check out this thread:
http://www.backyardchickens.com/t/1134783/permethrin-spray