Why do Sharks like blood? How & Why do sharks smell blood?

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Why do Sharks like blood?

Sharks are one of the top predators in the ocean that feed on flesh and blood. Their diet includes smaller fishes and other invertebrates and seals, sea lions, and other marine mammals.

Sharks are apex predators that had made them stay at the top of the food chain, hunting other animals and eating their meat and bones.

Sharks are opportunistic feeders, meaning that they try to take advantage of opportunities as they arise by feeding on easy meals that gets easily available.

Sharks are also scavengers. They eat dead fish and mammals or any other meat they can get.

So, it’s a natural innate behaviour of sharks to smell and get attracted to blood and meat, as it is the best way to find their target prey using their awesome sense of smell.

Sharks do really like all types of blood and over the millions of years of evolution they have adapted themselves to become absolutely intoxicated by the scent of blood, either the blood is of human or any other aquatic animal.

So, they do like blood and get attracted to it, not in the sense of drinking the blood with the ocean water. But, in the sense of finding the prey from which the blood is coming out.


They have a good sense of smell that gives the shark better estimation and registration of the smell to detect its prey either living or dead from miles away.

How and Why do sharks smell blood?

Sharks do have a great sense of smelling. In fact, the sense of smell is the most important sense of the shark to detect its prey.

Its sense of smell is so improved that it can easily detect about 1 drop of blood in about 1 million drops of water from miles away. This is like being able to smell one teaspoon of something in a swimming pool.

They use their two nares (nostrils) which are located under their snout lying on the ventral side of the head just in front of the mouth.

Each nare has two openings, one for water to enter and the other for water to exit. The water enters through from the nares and goes into the nasal sacs.

The nasal sacs leads to the big spaced nasal cavities, which gives the shark more time to detect the smells before the water leaves out through the other nare.

So, while the water passes from the nasal sacs to the big spaced nasal cavities, the water passes towards a series of skin folds known as olfactory lamellae that have olfactory receptor cells.

The olfactory receptor cells bear internally sensory hairs and their basal ends are connected with the fibres of the olfactory nerves.

The olfactory nerves passes the smell stimuli from the hairs to the olfactory lobe of its side of the brain.

This helps the shark to detect the prey and its distance from the smell of the blood. And, once the shark have identified the scent and decides to pursue, it starts swimming towards the target.

So, Why do sharks smell blood? Till now we were learning how sharks smell blood, and now we’ll know why sharks smell blood.

Smelling the blood present in water is the shark’s natural behaviour that it is built with from birth. So, sharks can smell either knowingly or unknowingly to find its prey very easily.

As already said, that they are opportunistic hunters and so they won’t miss any chance of getting an easy meal. So, smelling blood and flesh is a great feature to them.

As the water enters the nares and gets in towards the nasal cavities, the stimuli of the blood smell gets detected, and this helps the shark to know its prey’s location.

So, it is an involuntary response that the sharks get by smelling the blood out of the sea water.

Then, if the shark wishes it can go after its prey or it may not. And, this response of going after the prey is totally voluntary and is controlled by the shark if it wishes to do so.

Do sharks attack when they smell blood?

Yes, sharks do likely attack when they smell blood. It’s because when they get the smell of blood they do swim towards it in search of the prey either dead or alive.

For sharks smelling human blood and attacking him or her is very common, as humans are good source of meat that can be easy kills in water, when compared to fast-moving fish and seals.

It is to be noted that sharks have a hundred times better and powerful sense of smell than we do have, and so this is what that helps them smell the blood of predators from miles away.

Their powerful smell sensors better help them detect the prey from the blood and so they swim after their prey from miles away.

Hungry sharks are known to response more faster than the full-fed ones after smelling the blood and so they are more likely to attack the target prey if they have found one.

So, in simple words, you can say that the sharks can identify blood from miles away, but the scent doesn’t necessarily cause them to attack.

It’s their involuntary response that makes them smell. However, it’s a voluntary response that make them swim after the prey and attack.

Meaning that, after smelling the blood, it can take the decision of swimming towards its target or not. And, next if it had decided to swim towards the target then it totally depends on it, if it wants to attack or not.

But, the chances of getting attacked by sharks are more than being not attacked, as very often most of the hungry prey searching sharks get attracted to the blood.

Are sharks attracted to period blood?

You must note that any type of blood, whether it’s a drop of blood coming out of a cut finger or menstrual blood coming out of the female vagina, all is detectable by sharks.

In simple words, any bodily fluid let it be urine, blood, or any other body fluids, if released into the water is likely detectable by sharks.

Although there’s no strong evidence to prove that the menstrual blood don’t attract sharks. And so, as menstrual blood is also a kind of blood, it is very likely to attract sharks.

Sharks can smell their prey of choice from the amino acids coming from the blood and guts of marine animals.

In fact, the smallest to smallest proportion of blood components can be detected by sharks. So, it is always better to avoid going into the sea for menstruating womens.

And if you see, till date there is no positive evidence that menstruation is a factor in sharks attacking females.

However, there are many pieces of evidence that suggest that when the menstruating female swims, the water pressure will temporarily stop the flow of menstrual blood decreasing the chances of any blood being released into the water.

So, people often get confused and so say that the sharks are not attracted to period blood and menstruating women.

But in reality, sharks get attracted to blood let it of any type, because for them blood is blood, and the prey is prey, and nothing else they do think before attacking.

Why do sharks attack humans? Do sharks like human blood?

Sharks attack humans because it is probable that they may be considering them as an easy meal in water.

And yes, they do like human blood, but not so much as that of the other aquatic animals blood.

When in water they think about humans as slow moving animals as compared to the other fast moving seals and fast moving aquatic animals.

It can also be that sharks may attack humans out of confusion or curiosity. If a shark sees a human splashing in the water, it may try to investigate the matter, leading to an accidental attack.

Sharks may get confused by looking at humans who are probably surfing or riding boogie boards on the surface of the water. Confusion probably occurs because they may think surfers and board riders as that of a sea lion or a sea turtle. So, it’s very likely that they may attack out of confusion.

It can also be that the sharks can attack a human being thinking it its prey, if it had smelled its blood or any other body fluids in the water. This often happens with young sharks reported so far.

Some shark attacks may be a result of the shark’s natural instinct to defend its food source against all other predators. So, it may also be that the shark may have confused humans as their other competitors searching for the same prey.

Another reason may be that, sharks as predators at the top of the ocean food chain, they are designed to hunt and eat large amounts of meat. So, it’s likely that a hungry shark may attack any kind of prey they do see.

Are sharks attracted to their own blood?

Yes, there’s a pretty good chance that sharks may be attracted towards the blood of other sharks.

But, do sharks get attracted to their own blood is still not cleared due to the lack of proper evidence.

And, it’s pretty sure, that they can smell their own blood, but they do not attack themselves.

However, in some species, where cannibalism have been seen, there sharks can attack other sharks as predators if they smell the other shark’s blood.

If a shark is bleeding then yes, there’s a pretty good chance that another shark may have caused the bleeding. Such an attack may be not to eat the other shark, but due to fight between the two or those may be the mating scars.

While in some cases, it has been seen that some shark may eat other shark. You will find some degree of cannibalism in most shark species.

A lot of species of sharks eat other species of sharks and within a species you have larger, older individuals eating smaller, younger individuals.

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