Well so far in my life, I have had hermit crabs, a hamster, two budgies, and Daisy. I'd say the birds were the hardest to mantain just because they made such a mess, pooping everywhere and scattering seed shells all over the floor. I had to vacuum under their cage and table every day! Plus you add in the fact that they didn't even like me and devoured my fingers... it wasn't too much fun!