Exotic pets have exotic needs. Fish need a precise pH and temperature in their water. Snakes eat other animals and frogs may eat each other. Chinchillas need special sand to bathe in. Chameleons will only drink running water.
Small birds eat ground shells or sand to help digest their seeds.
You may need to purchase special equipment for an exotic pet such as a heater or special food. You will need to read a good book on caring for your exotic pet to be sure you aren't missing something important. Pet store sales staff can help and it would be a good idea to contact an exotic veterinary office for advice. Often, staff at local zoos will be of help referring you to special veterinarians when a pet is very rare and veterinary help is difficult to find. There are only a few veterinarians trained to treat these pets so find one before you need to.