Could I use sticks from outside as ramps for my rat cage?

The reason why I ask is because I don't want to get sticks from outside and there be parasites or something on them that would harm the rats. Would I need to clean the sticks, or would this be a bad idea all together. I know they also sell sticks and wood for ladders. (Trying to stay a bit cheap though lol) Also, I dont have rats yet but this coming monday after im done with my cage, im going to get two baby male rats =].