I had this experience several years ago. Ive had a ground blind built of sticks and brush in the same spot for close to 20 years. I just keep building it back up year after year. Opening morning several years about an hour before dawn, I got in the blind as quietly as possible and sat down on my seat. After about 10 minutes of dead quiet I stretched my legs out under the brush at the front of the blind and had a huge porcupine take an extreme dislike to my left foot. Talk about nearly dumping in your pants! That darn thing pulled me right off my folding seat. After a couple of minutes complete fright I finally kicked enough of the brush out with my right foot and whacked it on the head to let me go. Good thing had my steel toe boots on. Geeeez!