Are flea collars bad

Are flea collars a bad thing? Some say so, and I say yes as well. Most flea collars have chemicals that kill fleas. Ya, that is a wonderful thing isn't it? A flea-less cat or dog. But did you know that most flea collars have a chemical that sinks into your pets fat or skin. It stays there and creates pores of this flea killing gas. EW!!! Pores on your animal that stay there the rest of their life. Then what happens when the gas goes away. You better not think that the pores go away. No sir, they stay were they are. Then fleas can lay eggs in there and it will be even more difficult for your pet to get the fleas off. So you pretty much are torturing your pet worse.