From Satya:

Re: Bird can “read” human gaze (April 2): Lots of birds can read the human eye to some extent. Butterfies and house flies can also read human eye. Red robins and swallows have been my most recent experience.

I have noticed that most animals can detect when you are looking at them. This happens particularly when they feed. This is because they are most vulnerable at feeding time.

Other animals read the eye so they can defend their food while eating. You might notice a dog snarling at another dog at feeding time. This is very interesting if you get a wild dog and give it food. The dog will snarl at you as you look at it feeding but calm down when you look away.