Wiggle wiggle wiggle!
Gummy is displaying a behavior called "caudal luring."

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Wiggle wiggle wiggle!
Gummy is displaying a behavior called "caudal luring."
This is an interesting stress behavior that we don't see very often in corn snakes!
The tail wiggle that you see here is called caudal luring and it's distinct from the vibrational shakey-tail threat display. This is a defense maneuver!
Shakey-tail is intended to trick a potential predator into thinking the snake is a venomous rattler.
By contrast, caudal luring is a last-ditch effort to get a predator to attack a snake's thrashing tail instead of their head, while the head is focused on leading the body the heck outta danger. They may lose part of their tail, but they have a better chance of living to tell about it. Some snakes and other reptiles may use caudal luring as a hunting strategy, too!
This snake is definitely stressed, not hunting, so I recorded a 5-second clip and then focused on helping them feel safe and in control of their body by loosening my hold on them and letting them move freely through my hands. They stopped the behavior and we moved on to the next part of the handling session.
A tiny bit of stress with a positive outcome can inoculate against future stress. The goal isn't to prevent any stress from ever occurring, but to limit stress to what is necessary for proper husbandry (in this case, taking a length measurement and transferring to a feeding cup) and to work with the animal to help them overcome stress when it occurs.
This was really interesting to see! Daybreak was performing some caudal luring while we were outside. This tail-wiggling is usually done to attract prey, but it can also be an attempt to distract/discourage predators.
me luring your man within striking distance
To lighten the mood, here's little Sourpatch doing some fun luring. Probs one of my favorite snake behaviors. (sorry for the video quality, it was dark in there)