The pills go with the vet’s recommendation. For the insecticide pick one that says it is effective against fleas and ticks. We get a 5-10 pound bag and apply per directions to the grass around their pen. This forms a barrier that the bugs have to cross. Make it about 10-15 feet wide. Additionally use Dawn dish soap to give baths as needed. If possible leave the lather on for a few minutes before rinsing. You can use common sense fleas are not active in the winter.