Why do some people have three nipples?

Answer 1

Because they're special...:)

Answer 2

my uncle has one. during the time of the Salem witch trials, they were used as proof you were a witch-theoretically your familiar would nurse off of it and draw strength from it. But in reality, it is a birth anomaly. A supernumerary nipple (also known as a third nipple, accessory nipple, polythelia or polymastia) is an additional nipple occurring in mammals, including humans. Often mistaken for moles, supernumerary nipples are diagnosed at a rate of 2% in women, lower in men. The nipples appear along the two vertical "milk lines", which start in the armpit on each side, run down through the typical nipples and end at the groin. They are classified into eight levels of completeness from a simple patch of hair to a milk-bearing breast in miniature. Polythelia refers to the presence of an additional nipple alone while polymastia denotes the much rarer presence of additional mammary glands..
Considerations

Supernumerary nipples are a fairly common occurrence. They are generally unrelated to other conditions or syndromes. The extra nipples usually occur in a line below the existing nipple. They are usually not be recognized as extra nipples, because they are usually small and not well formed.

Common Causes

* Variation of normal development
* Hay-Wells syndrome (very rare)
* Ruvalcaba-Myhre syndrome (very rare)

Answer 3

You are getting some very strange answers most of which have nothing to do with the real reason.

Humans have mammalian ancestors that had whole lines of nipples on their bellies. You can see these multiple nipples today in many living mammals: dogs, pigs, cats, etc. Humans extra nipples are remnants that haven't yet disappeared over the evolutionary eons.

Answer 4

how many nipples to cats and dogs have....they have a series of nipples along the chest...as explained earlier about the milk line or mammary ridges that appear from the axilla( armpit) to the groin.
this appears both in males and in females...and from this milk line the nipples and breast develop. but during foetal life itself most of it dissappears except that overlying the chest region. both the breast and the nipples develop from this mammary ridge( yes even in males...whcih finally becomes rudimentary except in gynaecomastic cases).
a simple failure of dissappearance of this ridge newhere can cause development of breast tissue or nipples.
however development of breast tissue is extremely uncommon but nipples are common...and still more common is that the nipple persists on both sides so there are four and three is less common.
and yes most of the times they are misinterpreted as moles or stuff..and unless they look like a nipple they remain undiagnosed.
let me tell u some more of these anomalies that have been found in extreme rare cases.
1) whole of mammary ridge dissapears on both sides or one side( u can now easily imagine what can happen) no breast tissue or nipple on either or one side...called amastia and athelia
2)breast tissue not degenerating in males...gynaecomastia.
hope this has helped and invoked curiosity how other parts of the body develop and their related anomalies....this is embryology
so polythelia( more than two nipples) is a developmental anomaly and not genetic as many people have posted

Answer 5

It may sometimes be caused by a birth defect. Alot of times this happens because of the woman's hormones during pregnancy, or alcohol or drugs come to play. Not always is that the case though. I've seen that alot in China though, they say it can mean that the mother was supposed to have twins but it never developed the right way.......

Answer 6

its a genetic mutation. my boyfriend told me about this the other day and pointed out that he has a third one too. like how cats and other mammals have a set of six or eight. its from times when we may have had a 'litter', but we evolved out of that and came to only have 1-2 babies. but its kinda the same reason that people every now and then have 4 babies. its a vegistal (no point) structure, like the appendix

Answer 7

genetic mutation
nothing serious

and if youre a woma with three only two will work when youre lactating

Answer 8

Then that means they have a twin and that 3rd nipple shows where how the twins seperated at birth

Answer 9

you are mistaken my friend. although people often have bumbs and discolorations on the center of their chest that they claim are third nipples, they are not.

Answer 10

Same reason some people have 6 fingers.

Answer 11

its a genetic mutation