The amount of crickets that you keep will all depend on how many animals you need to feed and how much housing room you have available for the crickets. You will quickly work out roughly how much your pet eats each day/week and can decide how many crickets you will need to make sure you never run out of food. Make sure that you don't try and squash too many crickets into a small enclosure or you will just end up with large amounts of deaths and a hungry pet. If you have many mouths to feed or a single pet that eats a lot than make sure your cricket container is big enough to fit them all comfortably.