Howler monkeys are the loudest mammals on earth second only to the blue whale. Whats the purpose of all their howling? Alex tells you why, and shows you .\r<br>\r<br> Listen to the howls of the howler monkeys - one of the loudest land animals on earth! The howls of this species can travel through the .\r<br>\r<br>\r<br>\r<br>Animals are weird and crazy things. Theres so much about them we dont know! Here are some of the fun facts we DO know about animals.
