Hello!

I have a BP I've had for about a month. It seems that after he strikes his prey, and during the process of swallowing his food, i noticed that he bobs his head up and down. With the mouse in his jaws, he's move his head up and down for a few minutes. Is this normal? I tried to look for any info online, but it seems like this is what they call "undulating," and his perfectly normal? Do all BPs tend to do this? Thanks!!