Phasmids, or stick and spiny leaf insects, need fresh leaves (usually eucalyptus) every few days and a spray of water every day.
Instead of containing sand or dirt, Fascination's AntWorks ($20, amazon.com) is filled with a nontoxic blue nutrient gel so that ants need no additional food or water. Catch your own ants, or order them by mail.
Madagascar Hissing Cockroach
The large, wingless Madagascar hissing cockroach can't bite or hurt you. Keep it in a tank with a heating pad underneath, and feed it fresh veggies, fruits, and dry dog food.
Like the sound of crickets? Get an adult male (females don't sing) and keep it in a ventilated aquarium. Crickets will eat each other if not well fed. Try lettuce and oatmeal.
Originally published in the June 2009 issue of Parents magazine.