Giraffes spend up to 16 or even 20 hours per day feeding and can eat up to 145 pounds of food a day. Giraffes have long, muscular tongues, which can reach a length of 18 inches. Their tongues are dark colored, an adaptation thought to prevent sunburn. Thick saliva and tough lips help giraffes eat thorns without getting hurt. Giraffes are ruminants, which means they regurgitate their food after partial digestion and chew it further. The food than moves onto their stomachs which have four compartments.