Is it possible they developed a tolerance to permethrin?
Yes that's absolutely possible due to overuse building resistance. You can try switching to Elector PSP and only use it to treat an active infestation.
I am wondering if I should place permethrin powder on mom. I don't want to harm the chicks.
Permethrin is safe on chicks, though I'd just dust the mother and the chicks will naturally get dusted by going under her.
Yes that's absolutely possible due to overuse building resistance. You can try switching to Elector PSP and only use it to treat an active infestation.
I am wondering if I should place permethrin powder on mom. I don't want to harm the chicks.
Permethrin is safe on chicks, though I'd just dust the mother and the chicks will naturally get dusted by going under her.
