Gorillas are the largest apes. Adult males are about 1.8 metres (6 feet) tall and weigh up to 170 kilograms (375 pounds). They have huge heads, a bulging forehead and a crest with thick muscles on top of the head. Although they are portrayed as aggressive and dangerous killers, gorillas are in reality shy, peaceful vegetarians. They are extremely intelligent and can learn complex tasks. Each evening, gorillas make nests using leaves and twigs in which they curl up and sleep.
Question:
Why do the phrases “dressed to the nines” and “putting on the dog” mean very well dressed?