When I was young, monsters ruled the night. There were, however, some rules.
1) They could not get you if you were completely under the covers (really tough without A/C on hot nights).
2) Monsters could not get you when you were in the bathroom, so the first dangerous part was getting there. You had to sneak there so they couldn't hear you. If mom or dad heard me on the way, I'd run back to my room and hide under the covers, because my cover was blown.
3) After going to the bathroom, the monsters could hear you flush and would rush to try and catch you. Thus, each time I flushed, I ran back to my room as fast as possible (where I put my head under the covers). I always believed I had to be in bed before the toilet made its final gurgling "glug-glug", or I would be monster food. [This wouldn't be possible today with some of the newer, pressure-assist toilets that clear fast.]
As I got older, the changed a bit. After all, monsters got hot, too--especially with all that fur and those scales, so I figured I'd be safe it at least my ankles stayed under the covers.
To this day, even on the hottest nights, I still like to have my ankles under the covers.
A childhood belief about monsters

others believed things like this
- I used to believe that if I farted in bed, a monster would pop out through the covers and tickle me.Anon
- I used to believe that if i took the covers off at night i would freeze to death.— RockerGirl
- I use to cover my head at night because I thought monsters would give me a bad hair cut while I was sleeping!— Amy
- I used to believe that if you slept with the covers covering your neck, vampires couldn't bite you. — Moot
- I used to believe that undercover cops hid under covers/sheets. — Holly
- my sister used to tell me that manhole covers were direct portals to hell.— autumn