Dusting with 5% sevin powder

[magullage]

I dusted all my girls and Roos last night and it appears to have worked on all but the two with the infestations....do I have to wait seven days to redust or should I do it again? There are eggs and active lice on both of these birds...but no one else. Advice would be super.

 

[magullage]

It does appear that the population is down on both...but still active lice.