As an example, a rabbit could have 1 egg cup of pellets and a pile of hay per day, plus a selection of vegetables. One day it might be a cauliflower leaf and fresh basil/parsley and another day blackberry leaves, fresh grass and a small carrot.
DIY treat - freeze your guinea pig's or bunny's favorite fruit or veggie treat into ice cubes and give them as treats. This helps them cool down on summer days. Remember to always check with your vet before introducing human food to your pets.