http://www.newsweek.com/reindeer-sleep-multitasking-rumination-non-rem-rudolph-1855001

Some people, as the phrase goes, are so bad at multitasking that they "can't even walk and chew gum at the same time."

The same cannot be said of reindeer, however, with a new study suggesting that Rudolph and his ilk might be able to sleep and chew cud simultaneously.