Meet the massive bison -- the largest mammal in North America.Wild Life LOL Series introduces young readers (Ages 6-8) to some of the most amazing animals on the planet in a Laugh-out-loud funny way. Each book is brimming with colorful photos, bite sized text, wacky facts, jokes and riddles. It's hard to believe these powerhouses of the prairies eat only plants ... lots and lots of plants. Bison spend 9 to 11 hours a day feeding.