What caused the tick in Generation 1 to be resistant to Permethrin? *

The Gilchrist strain originated from a home with 19 dogs and had an exceedingly large brown dog tick population, which demonstrated resistance levels to permethrin and tolerance to fipronil

Explanation:

This medication is used to treat head lice, tiny insects that infest and irritate your scalp. Permethrin is also used to help avoid infestation in people who have close contact with someone who has head lice.