Some doctors say insomniacs should count sheep if they have trouble sleeping, but I personally find this quite exhausting. The sheep have a bad habit of trying to escape from the pen, and then it's work, work, work to get the stupid creatures back inside before a wolf or some other evil beast comes to devour them. Even if you do manage to fall asleep, you'll awake a mess of nerves and sweat worrying for the safety of those simple creatures.
No, the doctors have it wrong. If insomniacs want to sleep, they should count goats. Goats are similar to sheep, but have some sort of antlers with which the rowdier ones will try to attack other creatures - or even each other. Typically, I only need to count to several ill-tempered nanny-goats, and if the pen is small enough, they'll be butting each other before you can say "Capra aegagrus". After this point, it's only a short amount of time before the goats notice who else is in the pen, and sleep will surely follow shortly thereafter. The only downside with this method is the headache one wakes with afterward.