Loved this book! Part of this project started from wanting to make 4D creatures and train them to walk with RL. One interesting fact I learned is that ants would probably have 8 legs in 4D.

Why? Well, apparently ants have 6 legs because this allows tripod-gait, a simple leg movement that always keeps 3 stable points on the ground[1]

In 4D, you'd need 4 points on the ground, hence tetra-pod gait (4+4 legs).

You could of course do with less, I'd guess even as low as 1-2 if you have lots of muscles and good balance.

[1] https://dugas.ch/4d_creatures/tripod_gait.html