The Desert tileset seriously needs a screaming sound for lemmings falling in the quicksand trap (like the lemmings being eaten by the lizard in the Rock tileset or the frog in the Outdoor tileset), so one can know if a lemming was killed by that trap or not.
If you've added a screaming sound for lemmings falling off-screen, I don't see why it can't be done here too.
Valid point. I don't think it's major enough to warrant a dedicated update, but I'll make the change next time I'm updating the player in general.
Added for next update.