I used to believe that dogs and cats would poo out of the tips of their tails. I mean, that's why they had tails; that's what their tails were designed for.
A childhood belief about cats and dogs

others believed things like this
- That hot dogs were made from rat tails.Anon
- When i was little, i thought dogs poop from their tails.Anon
- When I was little, I used to believe that wind was caused by whales flapping their tails way out in the ocean.— Nanohawk
- I used to believe that waves were made by whales who lined up in a row and flapped their tails.— Passionola
- I thought a Monkey was just a baby Gorilla and when they grew up their Tails fell off!— Brainhead
- My sister and I thought cats and dogs were the same animal, the dogs were male and the cats were female.— Paul