Bats Behaviour

Bats are nocturnal mammals and are active once the sun sets. Being mammals, they have common mammalian characteristics such as warm body temperature and their fur. What makes them different from other mammals is that they are able to fly. Though there are other mammals that can so-called fly, these can’t be considered as flying but gliding. Furthermore, they have unique adaptations and behaviour to their respective habitats.


They are able to see at night not because they have night visions but because they send out ultrasonic signals that only they can hear. These signals bounce off any blockages, which makes it possible for them to navigate while flying. This process is called Echolocation.

The emitted high-frequency sound that bats create bounce off of any objects blocking off their paths and send the echo back to them. With the returning echoes, bats will be able to determine how far the object is from them, the size of these objects, their speed, and even determine the texture in a mere second.

Echolocation or biosonar allows bats to fly without bumping into trees or buildings if they are already living in urbanized locations. The high-pitched sounds they create from their mouths or noses are only audible in the ear of the bats and not on humans.

Bats have an inner ear as well as the auditory cortex in their brains that are adapted to understand the sounds made in the ultrasonic range. They use their tails to function as brakes. This enables them to do tight twists and turns whenever they are chasing and catching insects.

Though most bats use this specific characteristic, species like fruit bats are the ones using their sight to find fruits and navigate.

Most Fascinating Mammals

Among the amazingly diverse mammals, bats have interesting characteristics that will surprise anyone. The common ones you see may be a bit bigger than the smallest bat species, which is Kitti’s hog-nosed bat with a wingspan of 5.91 inches. The largest bats with the wingspan of 5ft and 7 inches are the giant gold-crowned flying foxes.

There are more than 1200 known bat species that you can find on earth, which makes them the second-largest order in the mammal's group. Also, out of all the mammals in the world, 20% of the classified species are bats.

Only Mammals that Fly

Bats are the only mammals that can fly. They have different adaptations that allow them to fly easily like their long arms that have finger bones that are light and thin. These allow them to manipulate and support the wing membranes.  

To fly, their body is also aided by the fused bones in some areas like the skull. This is what makes the bat lightweight. Though these wings’ main purpose is for flying, they still have other uses like forming pouches when catching or carrying preys.


There are different species of bat that feed on specific things. Some are only eating insects and some are into pollens while others are into fruits. Bats that are eating pollen are feeding on nectars. They fly from flower to another and at the same time help trees in producing fruits.

You may wonder how bats help in pollination when they only go out at night. Though bats only come out at night, there are certain flowering plants like calabash trees and cacti that only blossom at night. Since bats are only out during the night, they are the ones helping these night bloomers pollinate to produce fruits.

Adapting for Sustenance

Given the wide range of bat species, it also means that these species feed on different food sources. Some feed on blood, insects, and fruit eating bats hunt for fruits around their roosting nest. There are also some species that adapt to their living environment for them to gather or hunt food in the easiest way possible.

Another popular type of bat is the vampire bats. These bats, as what most people would assume, feed on blood. They have this feeding trait known as hematophagy. Their noses have thermoceptors that help them find blood vessels near the skin. They have a nucleus that is believed to make them see infrared radiation or heat. They use their sharp teeth to shave off the hair from their prey and penetrate the skin. The anticoagulant in their saliva keeps the blood flowing for them to feed on.


In contrary to what most people believe, bats don’t just live in caves. Also, they don’t live in just about any cave. The type of bats live in a place where they can get stable temperatures and where they can stay safe while they sleep. Not all caves have an adaptable environment for bats since every type has its specific requirements for a habitat.

There are certain species that can live hanging on trees without any protection. Some species like the Long-Snout Bats and Phantom-Faced Bats that only live in caves with very warm temperatures. Thus, making it incorrect to say or think that they can easily find a new habitat when people drive them away from their current roosting place.

As they return to their habitat, their body temperatures will go down until their bodies adapt to the temperature of the surroundings. While they are lowering their body temperature, so does their breathing and heart rate. The entire process is known as torpidity.

Unlike the bats in areas with colder surroundings, species living in hotter or more tropical areas don’t go through the same process though they also rest during daytime.


The normal gestation period of bats is about 40 days or 6 months. Bigger bats, on the other hand, may have a longer period for gestation. Most of the time, a pregnant female can only give birth to a single pup at a time. Though they can get pregnant several times during the breeding period, they can only give birth to one offspring each time they get pregnant.

Because of their small size, bats are the only mammals with the slowest reproduction process. At birth, the pup will only weigh about 25% of the mother’s weight. It is almost similar to a human giving birth to a baby weighing 31 pounds.

Female bats would build maternity colonies for the young bats. These colonies are areas where females are congregating for bearing and raising the young. Males, on the other hand, do not play any role in raising the pups.


Spring is when bats not only look for food sources but also mate with as many bats as they can find. There are mating calls done just like what the Brazilian free-tails bats do. They make sounds that try to attract their potential mates. Bats are also known for other bizarre behaviours just like when doing oral sex when mating.

Due to the huge bat populations in every bat colony, it isn’t really a problem for bats to mate. However, males and females are separated from each other until they are ready for mating. Once mating occurs, females get pregnant, create their maternity colonies, and raise their pups. When the pups are ready, adults would usually start to fly out of the colonies first and then followed by the baby bats.

Hibernation and Nocturnality

As mentioned, bats are nocturnal animals and sleep throughout the day. Because of this behaviour, they are able to keep themselves hidden from potential predators in their surroundings when they are vulnerable and asleep.

As the nighttime comes, they leave their roosting place and hunt for food at night. Since they don’t need daylight to see when hunting, they can roam around easily at night and hunt for food without being threatened by predators. In addition, this behaviour prevents their wings from absorbing too much heat.

Hanging upside down is their way of taking flight with ease. They use their feet instead of their hands to hold on tree branches or cracks and crevices inside caves. Bats can hold this particular position for long periods of time without the need to exert lots of energy. It only requires them to put a little tension on their tendons to keep their grips strong. The body weight is what closes the grip on the talons while they are hanging.

When Do They Enter Hibernation?

Once the winter season starts, bats start to enter hibernation. When entering this phase, bats will reduce their body temperature to be able to conserve as much energy as possible. They may also start migrating and look for a warmer and more humid shelter.

Since there are also fewer insects during the cold season, they settle in this long-term torbid phase. Bats use the body fat that they stored before the cold season. It is what enables them to go through the entire wintertime. Though they fall in deep sleep during this season, they still wake up every now and then to pee and grab some quick drink.

Before hibernation, they make sure that their hibernation sites has stable and cool temperatures. This is also the main reason why bats have different roosts during the winter, summer, and spring. They either hibernate, migrate or go into torpor or regulated hypothermia.

Potential Health Risks for Humans

Aside from the foul odour of their feces, bats are also known for their risks of carrying rabies. Thus, many are wondering if all bats carry this health risk.

Though it is impossible to know which bats have rabies, the risk still remains. Despite the small percentage of bats that are potentially carrying rabies, it is actually the main cause of rabies transmission to humans in North America.

It is the main reason why you should never attempt to handle bats without protecting yourself from getting bitten.

Understanding the Changing Behaviours of Bats

Since bats are able to adapt to their changing environment, they are able to survive despite the bat conservation efforts. As their options for roosting spaces or nests are reducing, they also tend to migrate to other places. They even start staying in places where humans are staying. Aside from forests, there are already certain species that are starting to build nests in both abandoned and occupied buildings and structures.

To avoid getting bitten, it is recommended that you take precautionary measures when you are trying to deal with bats. Keep in mind that bats don’t enter your home to attack you. Once they sense commotion and get into your home, they might get lost and disoriented inside your home. Thus, making it risk for you to try to grab it on your own and capture it.

Though bats are beneficial in pollination, some residents may find them a nuisance. You can try DIY solutions to capture bats or to drive them away. However, calling for wildlife exterminators can be your last resort in case the situation is no longer controllable or the residents want a safe extermination process done in their property.