More chance you might fall off and seriously injure yourself than some snake makes its way into your path. Sleep on the ground. Especially in colder weather. I have hundreds of nights on the ground. The Aussie thing about sleeping on the roof is good for them in certain areas where venomous snakes are prolific. It has played on our fears. If you can't get past the thought of a snake or bug, sleep in the back of the Jeep.