[Scorch]

FF-
They're tired. They work hard. No, seriously, they lay down to chew their cud. Like most ruminants, they feed relatively fast, then go lay down somewhere where they can see or smell danger approaching and chew their cud. Takes up a lot of their day. They like to lay in areas that have escape routes and a good field of view so they can see predators coming or smell them coming. If they bedded down in brambly areas they would not be able to see or smell or escape from predators. To tolerate flies and such, they flick their tails, which is a giveaway to someone with a pair of binocs and an excellent way to spot them.