Many animals with a strong sense of smell, particularly dogs, cats, and some reptiles (like iguanas), can detect menstruation through hormonal changes and the unique scent of menstrual blood, though their reactions vary from curiosity to indifference, while polar bears have shown attraction, and most other wildlife like wolves and bears aren't significantly affected, contrary to some myths.
Broadly recently conducted an investigation to determine what type of pets are most skilled at sniffing out someone's menstrual cycle, and the results might actually surprise you. It turns out that both cats and dogs are able to detect menstruation by odor and hormonal levels.
It turns out that both cats and dogs are able to detect menstruation by odor and hormonal levels. Of course, they don't actually have any scientific concept of what's happening in your uterus, but they do know that something is going on. Humans have many different scent glands within our genital area.
Beyond primates, it is known only in bats, the elephant shrew, and the spiny mouse species Acomys cahirinus. Overt menstruation (where there is bleeding from the uterus through the vagina) is found primarily in humans and close relatives such as chimpanzees.
“The smell women give off during menstruation is the same as a mare in heat. When stallions smell this they get excited and can become very dangerous for a woman on her period to handle.”
The "20% rule" for horses is a guideline stating the total weight of rider and equipment should not exceed 20% of the horse's body weight for welfare and performance, though many experts suggest a more conservative 10-15% is better for long-term health, with factors like horse build, fitness, rider skill, and activity intensity also crucial. It's a widely cited standard from sources like old Cavalry Manuals, but modern consensus leans towards it being a starting point, not a strict rule, requiring observation of the horse's comfort and fitness.
Medical research shows there is no reason why you shouldn't ride on your period. In fact, being outdoors and exercising can boost your happy hormones (dopamine, oxytocin and serotonin). Plus, if you've been horse riding for years your mind and body will be used to the movements.
It is important to note that menstrual bleeding in non-human primates is minimal. Furthermore, the lengths of the cycle and hormonal conditions have a substantial influence on the sexual behavior at the time when impregnation may occur.
Historically, the evolutionary origins of menstruation have been based on two theories: the ability to eliminate infectious agents carried to the uterus with spermatozoa and the comparative conservation of energy with menstruation compared to its absence.
When you're on your period, your body releases different chemicals and pheromones. Your dog can smell these changes and may react to them. Some dogs become extra cuddly, others may be more protective, and some just want to stay close by your side.
If your cat has become especially clingy when you're on your period, it may be able to smell the blood and is trying to investigate the cause. It could also be noticing a change in your routine, or potentially just trying to take advantage of any leftovers if you're eating or drinking more.
Hearing & sensitivity to sound
Some people wonder if cats can hear a baby's heartbeat. Typically, a fetal heartbeat becomes audible with a stethoscope around 18 to 20 weeks, so it's possible cats might detect it later in pregnancy, especially if they're snuggled close to your belly.
She either smells the blood or she knows you aren't feeling well in some way. Cats can be very perceptive. The other option is she's going through a period of clingyness and it happened to overlap with your time of the month.
There's absolutely no scientific evidence that washing your hair during your period has any effect on fertility. None. Zilch. It's a myth that somehow still finds its way into conversations, usually passed down from well-meaning elders who genuinely believed it to be true.
A shark's sense of smell is powerful – it allows them to find prey from hundreds of yards away. Menstrual blood in the water could be detected by a shark, just like any urine or other bodily fluids.
Swimming in the ocean during your period is generally safe. Menstrual blood doesn't attract sharks or increase your risk of infection. With proper hygiene and the right protection, you can enjoy beach activities throughout your cycle.
Using the calendar method, the Amish typically begins tracking her menstrual cycles for several months to establish the length of her average cycle. She then identifies the period of her menstrual cycle when she is most likely to ovulate based on the number of days before and after her average cycle length.
Background: Menstrual blood contains mesenchymal stem cells (MenSC), considered a potential "off-the-shelf" treatment for a range of diseases and medical conditions. Samples of menstrual blood can be collected painlessly, inexpensively, and as frequently as every month for cell therapy.
The average age of menarche dropped from 14–15 years in the early 20th century to 12–13 years in the present, but girls in the 19th century had a later age of menarche (16 to 18 years) compared to girls in earlier centuries. A large North American survey reported a 2–3 month decline from the mid-1970s to the mid-1990s.
In fact, approximately 98% of all mammalian species do not menstruate [1]. Menses is almost exclusively restricted to higher order primates, which include humans, rhesus macaques and baboons, with the only exceptions (until very recently) being a minority of bats [2–5] and the elephant shrew [6].
Graded-signals hypothesis. The graded-signals hypothesis was first suggested by Nunn in 1999, and suggests that exaggerated sexual swellings exist in female primates to indicate their fertile period to the males of the species.
Events of the menstrual cycle
Events during the menstrual cycle of humans and baboons are quite similar. The average interval between menses is slightly longer in baboons, 33 days versus the classical 28 days for women.
Pads Are *Not* Designed to Be Worn Swimming
If you bleed, then your blood will have nowhere to go; it will just mix with the water and become diluted. You may even notice a pink trail in the water (depending on how heavy your flow is.)
The 20% rule in equestrianism is a guideline stating a horse should carry no more than 20% of its body weight, including the rider, saddle, and all tack (boots, pads, etc.), to prevent stress, soreness, and potential injury, though it's a general rule influenced by the horse's conformation, fitness, and the rider's balance. Exceeding this can lead to gait asymmetry, higher heart rates, lameness, and discomfort, with studies supporting this limit, though some suggest 15% might be a safer threshold for preventing long-term damage.
During menstruation, you should avoid heavy/intense exercise, excessive caffeine, alcohol, salty/sugary foods, and tight clothing, as these can worsen cramps, bloating, and mood swings; also, practice good hygiene by changing menstrual products frequently (every 3-4 hours for tampons) to prevent infection and avoid strenuous activities if you feel fatigued or in pain.