There is a product called CedarCide. It's made of Cedar Oil and is supposed to naturally repell and kill fleas, ticks, and other insects. Their website says it is safe for humans and pets, and is made from FDA approved ingredients. I haven't used it but I'm definitely gonna look into this. Here is the website -
http://www.cedarcidestore.com/cedarproducts.html
Has anyone tried this yet?