(10) Burping and related topics. Sheep eating an adult diet generate a lot of gas, and have to get rid of it. If you don't have sheep, stand in the middle of a flock the next time you see one, listen carefully, and you'll notice a lot of quiet, regular, burping.
Picture: sheep from Kelmscott Farms at Common Ground Fair
You may pass a field and see a horse, on occassion, splayed out on its side snoozing, but you won't see an adult sheep do this. The sheep, the ruminant, has to stay upright, sleeping on its sternum, in order to efficiently clear gas.
Bloat is a serious problem for a sheep. When worried that a sheep may be sick, I'm always a bit relieved to have the sheep burp in my face.
(11) Intelligence. There is a cultural stereotype that sheep are stupid. My completely unfounded theory about this is that it is due to some combination of the following.
(1) Sheep are flock animals; people are not (or aren't as much). There are certain behaviors that sheep exhibit when they behave as a flock, that can look foolish to people. However, many of the behaviours are also exhibited by people, given the right circumstances. Example: 10 sheep will all try to cram through a door at the same time when trying to reach grain, although clearly no more than 2 can fit through the door at once. People at certain sporting events behave the same way.
(2) There are many different breeds of sheep. People have not valued intelligence in sheep and may have bred the brains out of some modern breeds, much as has happened with some kinds of dogs.
(3) People usually assume most animals are stupid.
The reason for this ramble is that it is important to realize that many sheep are quite intelligent, and you will have problems if you don't expect them to behave as intelligent flock animals. Sheep won't only find a way through a fence, they will sneak back in when they hear a car coming in the driveway, so that you don't catch them outside (thus ensuring the ability to sneak out again later). You may find that the sheep, peacefully grazing in your pasture, have been outside based upon suspiciously missing vegetation elsewhere.
A person meeting a sheep for the first time may have a hard time picking out that sheep from a flock later (unless it is the only brown one). However, sheep have no trouble differentiating between people they know and people they don't. Exception to this discrimination ability: sheep don't seem to recognize each other right after they've been sheared. There are a lot of double takes, which are pretty amusing.
Sheep form complicated and shifting alliances with in a flock, and this has ramifications for how much certain sheep get to eat, when and if the flock takes itself out to pasture, and how individual sheep react to strange people.
So...please don't expect every sheep to be stupid.