that I can use on the outside kitties we are caring for. We just had a mama and two kittens trapped and spayed/neutered and vaccinated. They are feral in the sense that we can't pet them (yet!), but they are always hanging out with us, come to the door and cry for food, love to play near us, etc. My biggest fear is fleas...we had a HORRIBLE infestation with my 2 indoor cats a few years ago (I think WE gave them to our cats after a camping trip!) and my cats aren't on any prevention due to age and illness (I really don't trust those chemicals, but I understand they are necessary sometimes) and our dog has severe allergies so we use a natural spray suggested by our holistic vet. Program is a pill that I could crush and put in each cat's bowl...I just have to very careful and watch each cat gets only one dose.