What can kill a plant in one day after it has come out the soil with a 3 foot fence around the pot. Please help! This is my only and last chance of the year to put out a few more seeds for my crop.

So this year in April 1st planted 9 plants. Some time in early May - 3 chopped in half - my best three huge promising plants, 2 left that were in a different area of the woods, and 4 others dead that were in the ground instead of pots. Early/Mid May - planted 5 more making it in all 7 plants. Late May - 4 of those plants dead after being only about half a foot tall at the most - and all had 2-3 foot high fences surrounding them. June 1st - moved all of my pots to the spot where I had my 2 surviving plants. Planted 6 more plants - 4 for good and 2 backups. Waited 3 days to go back to the spot and what the fuck do I get to see of my newly sprouted plants -- a mm of plant above the soil and a half-inch of root for every single one of them - only the ones I had just planted; somehow they can't eat my other 3 bigger plants - possibly because the beasts that killed the first 3 bigger plants was a rabbits or something of the like.

PLEASE, PLEASE, PLEASE HELP.
This is my only time I can plant again. Help me and tell me what is eating my plants and how I can stop them from devouring my infant cannabis.