Sounds human to me, carrots, esp deep ones aren't too easily pulled up as cleanly as you describe without the human "touch". Humans take them home and don't leave leftover evidence. Deer do munch on my carrot tops but I've never seen one pulled out of the ground.

Slugs or snails for sure. Slime mold couldn't be confused with a "mucus like substance." It's not also called Dog Vomit Fungus for no reason. Wayne

Here in mid-michigan woodchucks do such damage. Besides decimating gardens, they do costly damage to structures with their burrowing. They are usually too clever for Havahart traps, but if you were to try them, apples and other pome fruits are the best bait. Also there are restrictions on where the animals can be released. My neighbor hired an exterminator, who charged $200 for thee visits- no guarantee. (They did get one.) When the real estate is to their liking, more tend to move in though. They are diurnal, and can be asphyxiated in their dens at night. Your cooperative extension give you the details. One problem is the burrows have two or more opening which have to be covered simultaneously. Often one of the holes is on a neighbor's property! Probably you can't use this tactic under your house. This past summer I had the best luck with a campaign of harassment. When I find a new pile of dirt, I put litter box gleanings down the hole, then backfill with the dirt and pile boards and rocks on top. This requires constant vigilance, but I'm retired and am out in the garden anyway. When I see a woodchuck through the window, I run outside and scare it off. (I guess I'm my own guard dog.) One day I saw one munching on my snow peas, and chased her right into the netting. A fence at least 4' tall and 18" underground has been suggested, but again, they are clever. I'd like to be zen about this. Fretting over wildlife is not good for the blood pressure. I hope you don't have woodchucks. -Judy

Rabbits, most likely. That's the kind of damage they do. Some stems they eat and some they just bite off and leave. A good cage like Jim 1961 made for his Julia Child will work. Make yours just like his. Looks like Jim's is 16" high. It needs to be at least that high, don't go any lower. 24" high is even better. A big rabbit will be able to reach over a short cage as he stands on his hind legs and reaches over the top of it. They can stretch like a slinky! The fence wire Jim used with the 2X4" openings is good, chicken wire is too shaky. Rabbits will stand up leaning on chicken wire and feast on the rose bush they can now reach as it buckles in under their weight. Unfortunately baby rabbits can get through a 2X4" opening so a ring of 1' high chilcken wire fastened to the fence wire cage at ground level like a collar, is needed. Rabbits can destroy a rose garden. I'm truly sorry for your problem, but there is a solution, and a passive one that works 24-7. Looks a little odd, but it works.