I have a wood deck in back that a possum family has decided to move in to. Momma has been there for a few days now. She lines up her nose and eyes straight through the 1/4" gaps between the floorboards. This could be a decent photography opportunity, but it would be pretty intrusive for the family. Because of the gap size and the angle, I would have to be within 6 inches of them or so. So the question is - should I try getting a couple shots off, or should I respect their space and leave them alone?
I would say no, but only because I have been around possums. If cornered or threatened, they can get downright vicious and they move very quickly. If you've ever seen one in this kind of state, you'd appreciate the damage they can do.
Getting you and your camera inches in front of a mother with babies will probably result in (at least) your camera getting attacked. I'd look for another angle, one that affords a little more safety and a lot less disruption.
As Jordan says, its probably a good idea to get them out of there anyway. You can try a battery powered / cheap transistor radio. They hate rock / rap music.
The answer as is "it depends" but I would suggest you give it a try. Just keep quiet and be very careful, move slowly and make sure that other people around you are aware of what you are doing so they won't intercept with loud voices and questions. Non-bright clothes is also advisable.
Research the area, perhaps you'll find an opportunity to shoot from a longer distance. Putting camera on some long handle can be helpful, too: animals are less scared of non-living objects, especially when they move reeeeeeeally slowly.