It is normal for one testis to be slightly bigger than the other and for one to hang slightly lower than the other. The testes themselves feel like smooth, soft balls inside the baggy scrotum. At the top and to the back of each testis is the epididymis (this stores the sperm). This feels like a soft swelling attached to the testis; it can be quite tender if you press it firmly. Leading from the epididymis is the vas deferens. You can feel each vas deferens at each side at the back and top of the scrotum. They feel like soft, narrow tubes which pass up and into the groin. (The vas deferens carries the sperm to the penis.) Some people confuse the normal epididymis or vas deferens with an abnormal lump.