Hi Joanne, there are no animals or insects that I'm aware of that prey on ticks. However, if you do a search on the web on ticks you'll find a ton of information on how to control them. Here's a couple of sites that you might find usefull, Chemicals and Texas Ticks. Hope this helps!

I've heard that chickens eat ticks. I can't verify it, but it makes sense to me.

Guinea Hens adore ticks. Our newspapers have recently even had articles about it. If you have them, you won't need a watch dog either. They'll let you know if someone is coming!