While I agree that "uncomfortable" cage temperatures (ie. too warm) might cause a snake to be restless & want out, you should also know that these kinds of snakes are very active & may just be stubborn about rubbing their noses to escape. Remember that these snakes are active hunters, not passive ambush predators....travel is in their DNA. Larger cages seem to help, as does deeper substrate they can burrow into, & sometimes even more complex "cage furniture" may help. I have kept & raised bull snakes & gopher snakes in the past and I like them a lot. What size cage is yours in? I know how frustrating it is to have a snake rubbing their nose, and it's not harmless...it can lead to infections, besides being not so pretty to look at.