If you're in an area with ticks, I don't think there's really any way to 100% prevent them. But chickens get rid of external parasites through dust bathing, so making sure they have a dusty, sunny area for that is your best bet. That being said, I do not believe that Alaska has ticks. (Although I could be wrong.)
Since we got chickens, we haven't had any ticks around. They are usually a problem in the long hot days of summer. I guess ticks are afraid of chickens. On the other hand, we had very few bugs in the garden since the chickens came. Interesting coincidence?