I have discovered something that annoys me, though, at last. I killed some crabs by Seyda Neen when I first started. I just went back there and discovered that the dead crabs were right where I left them. So... Corpses stay where they are forever? They don't rot away, or get eaten, or anything? Every single thing I kill will remain where it falls forever? And does that mean there's no randomly-generated critters anywhere? Each enemy/NPC is coded from the start, and once I kill them, they will never be replaced? The crabs will quickly face genocide, and crab meat will become a priceless delicacy?
Is there a mod that fixes that?
As many have said previously, you can hit the "dispose of corpse" option when selecting them, you get everything in the creature's inventory and the body is... disposed of. However, they do disappear on their own, as long as you stay away from the cell they are in for three game-days. The important thing is the distance - for interiors and dungeons that's not a problem, go outside and come back in four days and you're good, but the game has a
hazy definition of what's close enough to load the corpse data out in the open world. So corpse disposal is your friend.
Also, there will be some bodies that
are permanent, you can tell by trying to dispose of the corpse - it won't let you. I always take advantage of them as a nice place to store loot - these tend to be in convenient places.
That being said - If it has a proper name, it's not going to respawn after you've killed it and gotten rid of the body. Generic critters will though, eventually. Generic bad guys sometimes will. But some don't.
As far as a mod to speed up the process - no not really. It's controlled by a game engine process that has been the bane of Morrowind modders since the beginning. Best just to do the corpse disposal outside.
*Fake edit* ninja'd.