Back in the Spring, my husband put down insecticide on the lawn to kill ticks. We had a really bad tick problem and our dog was coming in with several ticks on her a day. The bag said to apply once per season. Our chickens have been in a run and not exposed to that area. We would like to expand our chicken run but it would be over part of the yard where the insecticide was applied. When would it be safe to expand the run? I don't want to do anything to hurt the girls!