Most things I've read say chickens will seek out and eat ticks, guineas are the masters of tick eating though. I'd love to have them but oh the noise! and I wouldn't want them in my neighbor's yard. Ticks can get on chickens but typically the deer, wood, dog ticks aren't to much of a problem for them.
Poultry ticks are different and can be an issue but orange peel oil based products plus the normal measures used to control poultry lice and such will usually get them under control from what I've read.
I didn't want to use possibly unhealthy chemicals so I did some research and made my own spray deterrent to put on my hat and clothes out of garlic, vinegar, water, a little neem oil and eucalyptus oil - wow it stinks really bad but it also really worked. I haven't had any ticks on me since I started using it. This also should be safe for use around chickens cause you can use neem oil to cure scaly leg