I feel like this is a silly question, but I'm not sure how small I need to be cutting up their treats? I currently am giving them a small serving of something like cucumbers, apples, strawberries, etc. I am cutting them up into tiny pieces so they don't choke, like maybe a half centimeter on each side. Is that too small? Not small enough? Will they try to eat food that is too big for them and possibly choke?