In the goblin fort I tried to send my raven familiar ahead to scout around the area of the sleeping goblins and bugbears, but when I used an action to fly down to where they are, it woke up and alerted all of the bugbears, the sleeping goblins that were very far away, and all the other guards in the area were alerted and started combat with my familiar.
Logically a single bird flying past a group of sleeping goblinoids should not alert the entire fort to attack.