I've never used flea collars but I've been told that they just don't work. Since my cats are indoor only, I used to think that they would never ever have a flea problem. I was wrong because if some one else in my building has an animal with fleas then they can jump on me and then I can bring them in to my cats. You can also bring them in just by being outside in the grass. Now I buy the large dog advantage over the internet and then I measure the correct doseage for my cats. Since I live in a fairly mild climate, I have to use it year round. I've never had a problem since. Good luck.

Please don't ever buy any over the counter flea drops like Hartz or Bio Spot. This has been proven to kill cats and dogs. I still don't know why they continue to sell this. I only recommend using things that vets sell in their office.