Knots are how Alphas tie or “knot” themselves with their partner during sex. Knots are usually found in canid species. This is usually a tissue attached to the shaft of the canine and is what ties two canines together during mating. This is to ensure the mate catches and the sperm is usually kept strictly inside the mate. The knot itself is a tissue that swells during intercourse and is filled a fluid that ensures it stays swelled. When this occurs this is called "tying" or "knotting." Now, in the omegaverse, unless you’re doing a story based on people turning into werewolves, you won't usually get the candid structured penis. If your going with just humans or hybrids, then your stuck with the humanoid reproductive organs. The knot in this case is tissue that isn't visible outright. This tissue is located at the base of the shaft of Alphas and tends to subtly swell during sex. It usually is fully swelled when an alpha is close to climax and then it is shoved into the mate, subsequently tying or knotting the Alpha and there partner. Knotting/Tying and what happens afterwards When the knot is fully shoved into the cavity of an omega, it becomes essentially locked inside. This is due to in part of the muscles in the anus or vaginal cavity clamping down on it from pleasure and the knot being abruptly shoved in. Essentially the body can't adjust nor resize/shape in time to easily release the knot. Omegas bodies will automatically react to try and hold their Alpha close, and try and insure that they are impregnated. It is a biological response built into all omegas, and not a conscious choice, rather the clamping is just an involuntary and unavoidable response to being knotted. Once the knot is in, it usually stays in for thirty minutes, an hour, or longer. This part is up to the writer. However, during this part the shaft is able to released sperm into the body without any seeping out. The amount released during this time is up to the writer and if they want to specify the amount released or just want to exaggerate the amount released for when the tie is finished. Speaking of finishing, when the alpha's knot is fully swollen and locked inside, it will stay that way typically. However, it goes down after a while. Inevitably, this will cause semen to leak or seep out. But this occurs when the knot has gone down enough it can be removed. However, the knot can be removed at any time the mate desires. Though doing it when the knot has just been inserted or when it hasn't gone down just enough can cause pain for both parties. Now to sum up this entire chapter... The knot locks two mates together and in time can be removed without discomfort or pain, but can be forcibly removed.