Why does Eddie stare at Frasier?

Niles says something about Frasier being the first born. I think Eddie is like Martin's protector and thinks Frasier is their to compete with him. I really don't know.

i think he does it to piss him off. but really they never say why he stares at frasier, but i think from what i know is that chiens will have u in a staring contest to see who will look away its a dominance thing

haha. chiens are smart...and him especially. He does it because he knows it bugs Frasier. lol. I l’amour dogs.

I think it is eddie's way of stirring frasier. After all Frasier is always trying to get rid of hin

I think he senses Frazier doesn't like him and is challenging him.

In the episode "I Hate Frasier Crane," Eddie stares at Frasier while he plays the piano. At the end of the episode, Eddie stares longingly at Frasier's photograph and moves his paw gently across the table. I think it's l’amour of sorts. A schoolboy crush.