Oh no! I recently moved from CA to the Midwest, and I haven't really let Max out much yet! My brother's cat got fleas, and my parents' cats too. They just use those flea collars and drops on the back of their neck. We had a miniature pincher when I was little and he would bleed sooo much from them! The other min pin we had would get them, but she didn't get such a bad reaction.
That's terrible that you have to take her in all the time! I don't like when any permanent answer is medication! I hope someone else knows! I've heard of people putting flea stuff in their yard, but that sounds a little toxic!
hope someone else knows the answer for Possum!