Trancing / hypnotising / tonic immobility are all terms used for this act. Tonic immobility (TI) is a transitory and reversible state of profound motor inhibition that can be induced in susceptible species (Klemm 1976).
Unfortunately the internet is full of ‘cute’ photos of rabbits being made to lay on their backs. Many people in the showing and exhibiting world will also do this. Sometimes people will do this to groom a rabbit. Some people think the rabbit enjoys it and is relaxed…This just is not true 🙁
The rabbit is actually extremely scared and pretending to be dead. They are a prey species and will naturally act dead if threatened. Their heart rate increases along with their stress hormone levels (corticosterone). This has been scientifically researched and one recent study was undertaken by Dr Anne McBride and Vet Anna Meredith.
Please check out this very important blog post from The Rabbit Welfare Association and Fund: