Take tiny steps towards each other until you no longer feel comfortable getting closer. Now measure your the distance apart. They thought the robin looks bigger and fluffier partly because it actually has more down feathers than it does in the summer, and partly because it has those down feathers fluffed out for better insulation. The pupils are so small to minimize brightness on a sunny day. It's a little hard to tell, but the iris of a robin's eye is gray.
Many eyes are more likely to find food and avoid predators.
A large flock of birds is not camouflaged well - so bigger is better. And last but certainly not least - they find companionship during the long winter months. Robins eat fruits that sometimes ferment or get spoiled, and seeing some robins get sick may sometimes warn others to stop eating from a particular tree. Answer only ONE question in each e-mail message. In the body of each message, answer ONE of the questions above.