It's completely normal! I have a corn snake who does this in her tank (she's my only reptile in a tank) and sometimes I'll see my ball pythons doing this in their tubs. They can be funny at times.
But I agree that your snake is probably going into shed. Here are a few tips for you so you don't have to worry about what's about to happen! I just had my 2000g normal female shed for me tonight. She looks spectacular.
- Limit handling during this time. Some snakes gets pretty nippy because they can't see well
- Try to keep your humidity 60%-70% - cover 3/4 of the screen lid with a damp towel and mist a couple of times a day. That will help to keep your humidity up which will allow them to shed in one piece without any of it sticking to their back, neck, or heads (the most common areas for a stuck shed)
- You're snakes eyes will go blue - it's nothing alarming!
- anywhere from 2-7 days after your snakes eyes go from blue back to normal, you should find a shed skin in the tank! - an amazing thing to see even know when I've got 10 snakes.
- Pull the shed out and examine it to see if it's in one piece with no broken places. Be warned: some ball pythons will poop when they shed so the shed could be a little dirty.
- It's up to you if you want to feed during this time. So don't like to eat, some will. Several of mine will eat in shed if I let them. There is a little bit of a risk to feeding while in shed. Their skin gets stretched after a meal and if the skin is loose because it's about to be shed, it can dry and constrict the snake which could kill it. Now, this is a minimal risk. I've fed all my snakes in shed with no issues (for those that eat in shed) - this risk was pointed out by another member on here. It's up to you to decide what works for you and your snake.
- Because we all like pictures, show us some pictures of your baby after he sheds!