If I cast the find familiar spell and summon a familiar, then I can look through my familiar's eyes, hear through its ears, and communicate with it telepathically. (It is not a blind or deaf creature. If the question of whether it can understand my thoughts is an issue, then assume I am a warlock and my familiar is an imp.)
I tell the familiar to stop for a moment so I can make an active effort to concentrate on what I see and hear. Therefore, I roll a Perception check.
Do I roll it with the familiar's perception modifier, or my own modifier? Or one roll for me and one roll for the familiar?
Best Answer
You both roll.
Perception is a skill, not a sense. Two people see exactly the same thing, and one of them notices a small detail or something out of place that the other does not notice. (Sherlock Holmes: "You see, but you do not observe. The distinction is clear.") When your own perception skill increases with more levels, it is not because you magically grow a better pair of eyes. You learn how better to utilize whatever eyes you are looking through.
You and your familiar are two different creatures looking at the same picture. You both can apply your observational skills to that picture and tell each other what you notice.