If a dart is projected with the correct force, then it will only sink as deep as the needle. The gel collar helps ensure the dart does not "back out" upon detonation, thereby delivering the complete contents of the dart into the target. They work very well for what they are. Pneu-dart offers a barbed needle. This is the dart of choice in most scenarios that involve chemical capture. Simply delivering medications is what the gel collar is intended for. If you use transmitter darts, the only dart to use is the barbed ones, as you want the dart to remain in the animal so you can find the downed subject. As far as the animal lying on the dart and pushing it into themselves, one of 2 scenarios have to be true. 1. the dart was delivered with too much force and has not only penetrated the dermal tissue, but has also penetrated into the muscle, abdomen, etc. 2. the dart has been placed on a spot of the animal's body that is not suitable for the purpose. If you dont believe this, take a 1/2' diameter rod and try to jam it into a heavy muscled area of an animals body. It will not even penetrate the dermal tissue unless subjected to a tremendous amount of force concentrated to the area of the rod, like striking it with a hammer. Chasing a partially tranquilized animal to remove a dart before the animal succumbs to the chemical induces stress that will elevate the lactic acid production in the muscles, producing a more likely possibility of capture myopathy. The best advise I can offer when darting is PATIENCE, PATIENCE, PATIENCE, PATIENCE, PATIENCE! If you are concerned about retreiving a dart that becomes lost in tall grass, get a cheap metal detector and after all is done, scan the area with it. You would be surprised at how easy this is. If you use a barbed dart, the barb can only be backed out by maling a small cut in line with the barb. That is why the darts have lines marked on their bodies that indicate the orientation of the barb. Regardless of the type of dart you use, ALWAYS clean the wound and fill and coat it with wound with an antibiotic creme, not a petroleum based ointment. Moisture promotes tissue growth and a creme in the wound will heal it much quicker.