I'm fairly certain the OP is housing all the snakes together in that large tank. Correct me if I'm wrong.


As per your original question, I think its quite common for a snake who has just eaten to cruise a bit, although I think in this case you are probably underfeeding. Hatchlings straight out of the egg eat hopper mice. Bump her up to adult mice. I would get a scale and start keeping track of their weights. Feed 10-15% of the snakes body weight once a week and you should notice the cruising after meal time drop off.