These begin at puberty and officially designate the secondary gender. This might be painful, especially for male omegas and female alphas as they finish developing their internal organs.
Heats and ruts will continue to occur for omegas and alphas until their menopause, although these can often be extended to sync with their mates.
Ruts occur three to four times a year in alphas and last around 3 days. During this time, the alpha will feel aroused, produce increased levels of sperm (up to triple their usual amounts), have a higher body temperature (similar to a mild fever), and may become more aggressive/possessive towards their mate and/or den. While alphas can have knots outside of their ruts, these are often longer, usually 30+ minutes.
These occur only in omegas twice a year. Although omegas can get pregnant outside this, this is their most fertile time, and often sex during this time will result in pregnancy. Modern birth control has been beneficial in reducing those chances.
How long a heat lasts varies greatly among omegas, though the average is considered to be 5-10 days. During this time, the omega will feel aroused, produce increased levels of slick, and have a higher-than-usual body temperature (similar to a mild fever). These symptoms can vary from being a background ache to being completely bedridden, and will depend on the omega's age, health, romantic relationship(s), etc
One of the best ways to alleviate the symptoms will be through orgasms. If an omega has a partner to help them during their heat, their cum (sperm) will be even better as the omega's need for being bred is being fulfilled. This can also reduce the length of the heat, if the omega's body feels it has 'completed' its task.
Heats and ruts can be triggered by the other. This only occurs if the alpha is in close proximity to an omega in heat for extended periods of time (and vice versa). However, milder symptoms of heat and rut may not affect the other as strongly, and thus can be resisted for longer. If a heat/rut is triggered, it will throw the affected party's cycle out of the loop and may take longer for them to regulate it again.
Alphas and omegas who are together will slowly start to synchronise their cycles. Alphas' ruts will usually lengthen (and therefore decrease in frequency) to better match their omega's heat. This can be beneficial to those who are trying to get pregnant, as sex during rut and heat has the highest chance of taking.
If one party is older than the other, their heat/rut can often trigger their partner's, and the partner is often able to continue having children past their menopausal age. This is only possible if neither party has already hit their menopause. However, this can have other impacts on possible children due to the parent's older age.
Heats and ruts are when an omega or alpha is at their most fertile. Over time, many birth control options have been created, though abstaining from intercourse is the best possible option. Some of these include:
Condoms - these are specially made to be long-lasting and hold more fluid.
Heat/Rut Aids - these are specially designed sex toys that can imitate the sensation of a partner in rut/heat, which can help alleviate symptoms.
Long-Acting Reversible Contraceptives - these include options like IUDs, implants, pills, and injections.
Birth-Control Pills - these are only available to omegas and include specific ones to take leading up to and after their heats. There are some options currently undergoing testing for alphas which will decrease their sperm potency.
Suppressants - these are often oral pills that can be taken regularly, which will dampen the effects - both being emitted and received.
Blockers - these are often a last-minute option (taken early on/right before onset) to help postpone the current rut/heat, and will be active as long as they are being taken/in the body. However, consistent long-term use is not advised as the person can become accustomed and will need larger doses (which can be fatal).
Herbs/Tinctures - these were the common method before modern pharmacology and are still used by some today (especially in rural/indigenous communities).
Pups - children under the age of 2 will often emit hormones that can indicate to an alpha or omega that the person is already busy taking care of a young child, and is not yet ready to have another one. Prolonged contact with one will often pause the heat/rut cycle until the omega/alpha may be better prepared to take care of another child. Alphas or omegas who do not want to have (any/more) kids can use this as a form of birth control. Due to this, kindergartens will often be staffed by betas and alphas/omegas who don't want/can't have kids.