Looks like rat to me. Watermelon seeds are too small of an incentive for squirrels. Get a cat or two! They are much better than dogs at deterring rodents because they are proactive. I have 3 of them and they spend 90% of their time napping in my garden: squirrels stay at bay, possums also ( except for one that they tolerate on the fence only - not on the ground-) birds do not pick my fruits or vegetables, no rats, no mice = peace of mind. With nectarines, apricots, grapes, plum, pears, tomatoes, cantaloupes, watermelon etc, in my garden, there would be rodents all over the place if it wasn't for them! If you do not want a cat as a pet, associations are giving "barn cats" they are neutered microchipped and vaccinated, they live in barns/sheds and they do their hunter job. But you need to provide a safe place where they can go when it is too cold or too hot, water, food, vaccines, and vet care. Mine are well fed and are spoiled pets so they don't "over hunt" and sleep on our beds. They run after pests but stop the chase as soon as the critters are out of the garden. Good balance. Squirrels are staying high in the trees ( I like squirrels as long as they don't eat my fruits) I keep a stepladder in between my tomato plants, the cat lays on the upper stair and the birds do not even think about my tomatoes: problem solved.

I would have to say it is a bad case of sunburn. YOu probably put them outside for the first time and put them in direct sunlight. You have to harden them off gradually when going from indoors and artificial light to outside in direct sunlight. Start with putting them outside in the shade for a couple days for an hour of two per day. Then increase the sun exposure and the time outside gradually day by day. Your plant won't die, but some of the leaves will likely die off. No big deal. They will typically be the older leaves. So, at this point, you plants are probably hardened off pretty well even though you sun burned them in the process. It probably wont need any more hardening off. In the future, do it slowly and gradually. It should take a good week straight of gradually increasing their sun exposure. Also be careful of wind as the plants are not used to it and therefore they haven't yet built up a lot of strength in their stems. Wind exposure should be limited early on as well or you may find some toppled plants when you go to bring them back in. Bruce

Depends on how hot/mild you like them. I favor chocolate habanero and fatalli peppers in flavor. But I also like a good ghost pepper hot sauce home made. Some like Hungarian hot wax peppers most big box and nurseries carry them more mild type of pepper.

Maybe you could wrap a copper mesh scouring pad around the base, 2 or 3 inches above the base, and a half inch or so below the soil line, so that you dont disturb the roots. If it's mice or voles, and you place traps, please place the traps under a bucket with small access holes at the base, and a rock on top of the bucket, so you don't injure someones pet cat or dog. The smell of cat pee might also frighten away mice and voles, you could spread wet sand from a catbox. Other scent deterrents are coyote urine, which you can get at a sporting goods store, or some gardeners have used soap, perfume or human hair. Some barber or beauty shops might save you a vacuum bag full of hair for this purpose, if they know about gardening. You could wrap some hair around the base, it will biodegrade. Looking at the ends, does the stalk look chewed or torn? The stalk could have been accidentally pulled apart by a dog or person running past that caught a foot under the vine. I had to put up a 2 foot chicken wire fence to keep out rabbits, a fence like this would also keep tripping feet away from the base of the plants. Good luck, hope you get some peas. If you know how to clone, maybe you could cut up the still fresh, detached vine into 4 inch pieces and put cloning powder on them and stick them back in the ground, to replace the lost plants, it might regrow faster than reseeding. Does anyone know if you can clone peas, would this work?