I believe the gods love the animals like we do so, for ravens there is the story of huginn and muninn you can search of if youre not familiar with it and then its the number 3 which, if its a sign might have an importance but you know better. It also might be a sign that one of them, out of the blue just came and told you something which I dont know if its unusual or not but im sure it would not bother if it hadnt got any reason to do so. then theres body language, was it scared, frustrated or just liked you and wanted to say hi? Again you know better, especially if it was a sign because its meant for you! I hope I helped