Rabbits have aradicular hypsodont teeth, which means that their teeth continue to grow throughout their lives. While this might sound like a pain, rabbit owners can control teeth growth by feeding them foods like hay or grass.
Chewing on hay helps them wear out their teeth and bring them down to normal size, while grass contains silica that prevents their teeth from getting too long. If rabbits are fed muesli, it could cause their teeth to become too long and cause selective eating.
- https://www.coolkidfacts.com/rabbit-facts-for-kids/