My mother apparently still believes that those little flies you find on over-ripe fruit "just form there", kind of out of thin air. Apparently the fruit produces them spontaneously. She's 60 this year. Well. On the other hand, until recently my sister (now 34) believed that the muck you get on your windscreens is caused by flies and bugs relieving themselves (yes, sh***ing on them). She used to take it quite personally, too.
A childhood belief about creepy crawlies

others believed things like this
- My sister thought a fruit machine (the gaming device) could turn one item of fruit into another.— Richard Davies
- I use to believe that dragon flies and fire flies were fairies— lady eberly
- I used to believe that flies were called "bloody flies"!— Angelface
- I used to think that raisins were dead flies. I only recently started to eat them again.— Toinette'
- When I was 4, I thought that if I ate Fruit Gushers, my head would turn into a fruit. — Joe
- I used to believe if you ate a seed from a fruit, a tree of that fruit would grow inside you — kels