Here is the story with ticks as I understand it. Many times wild caught animals come in and are proclaimed clean. Ticks can hide out in the cloaca for many years. Then, when a female lays eggs, the tick comes out with the eggs. The tick will then lay eggs on the snakes eggs. The ticks have evolved over time to have the same incubation time as baby snakes, and the baby ticks will hatch with the baby snakes, and get on them this way.

My story goes like this. I bought a ch girl in 2003 (our fist Ball python, so she got plenty of attention, and was looked at alot). She bred in 2004, but reabsorbed the follicles. She bred again every year since then, and laid eggs in '06, '07 and 2008. She has been in my care for 5.5 years now. This year, after she laid eggs, I washed her and found a tick on her. This is the first tick I have ever seen in my collection. She laid eggs three years in a row before I ever saw a tick. So, I can only guess that the tick was hiding in her cloaca, and finally decided to emerge.