SuperPet Critter Canteen Bottle (8 oz) Super Pet Critter Canteen is so refreshingly easy to use - just fill it, cap it and hang it. Critter Canteens feature a unique spring-loaded sipper tube designed to reduce leaks. A free wire bottle hanger is included inside every bottle. Super Pet's 16 oz. Critter Canteen is perfect for chinchillas, guinea pigs, ferrets or other critters.