I use these shells to feed my two cockatiels. Seed mixed with chopped green, fruits,and vegetables are placed in the shells on the bottom of their cage (lined with paper). The shells are placed a few inches away from the edge of the cage. When the birds tip the shell to get to the "stuff" they prefer in the shells the food does not spill onto the floor. Later they will walk on the bottom of the cage looking for "stuff" spilled onto the floor they may now want to eat.