PROBOSCIS MONKEY: Have a look at that schnoz. Pretty outrageous, right? I bet you're wondering why an Old World primate like the proboscis monkey needs such a colossal honker. Doesn't it just get in the way? Actually, it does. In old males, the nose can reach nearly 7 inches (a quarter of the body length), which means these guys have to push it aside just to eat. But the tradeoff is worth it. Female proboscis monkeys find males with big noses pretty irresistible. The male uses his nose to make loud, distinctive warning calls when he senses danger. The "kee honk" sound of the male is produced when sound waves from the mouth cause the nose to resonate. When the monkey becomes really agitated, the nose swells with blood, making the warning call even louder and more intense. Perhaps females feel safer with males that are better at warning the troop of danger.