On a remote (imaginary) island, there are 11 snakes and a single mouse. As you’d expect, snakes eat the mice. But contrary to what you’d expect, when a snake eats a mouse, it turns into one.
The snakes live by only two rules:
1. Don’t get eaten.
2. Eat mice as long as rule #1 isn’t violated.
How many snakes and mice will there be left on the island?
Five hundred begins it, five hundred ends it,
Five in the middle is seen;
First of all figures, the first of all letters,
Take up their stations between.
Join all together, and then you will bring
Before you the name of an eminent king.
I lack much reason, but often rhyme,
And require logic to pass the time,
To get the words to tell your kin,
Look for clues that lie within,
Though all are different, they act the same,
The answer is practically in the name.
Light. Without light you wouldn’t be able to see anything. And light is made up of all the colors of the rainbow. Adding light to a word can mean it weighs less and light has no mass.
This walks on graves at night yet in homes during the day,
Men are scared of it, women like it, children play with it,
It lives on dates and salt,
It is covered in hair,
Its name starts with ‘M’ and it is mentioned in the Quran.
Moths.
Most species of moths are nocturnal, yet they are attracted to light and can be found in homes. Men, in the most generic sense, can be scared of moths (see Mottephobia) as well as the damage they can cause as pests to bee hives, grain, flour, trees and agriculture. Women like moths because of the silk they produce. Children frequently chase and play with moths. Moths are attracted to salt and love to eat rotting fruit (such as dates). Some species of moths are densely covered with tiny hairs and of course it starts with the letter ‘m’. Lastly, moths are mentioned in the Quran (101:4 (Asad) [It will occur] on the Day when men will be like moths swarming in confusion)
Getting older. Sad but true, and there’s nothing anyone can do to stop it. If you thought of breathing, it’s not entirely accurate because not everyone takes a breath at the same time. Living is an arguably suitable alternate answer as well.