They're trying to keep from falling off! These are terrestrial animals - not climbers.

I suggest you don't let your snake wrap around your neck. You can drape him around your shoulders or have one hand on his tail at all times. His tail is his weakest point, so if he is wrapped tightly on anything, you can grab his tail to unwrap him.

These guys can be surprisingly strong and have the capability of squeezing your windpipe. You can find yourself in a lot of trouble.