Ants can enjoy sleep like most other living organisms, as their activities get disturbed due to sleep deprivation leading to sluggish behavior after continuous work.
Do Ants Sleep With Their Eyes Open? Ants sleep with their eyes open, as they do not have eyelids that help them blink and close their eyes. Most commonly, insects lack eyelids as their eyes are dry, and open eyes do not pose a risk of infection and damage due to dirt and debris. In addition, ants do not get disturbed by external stimulation when they are in a deep sleep. Furthermore, it keeps them in a state of alertness, and open eyes can help protect them from invader attacks.
You must have never noticed a sleeping ant in the surrounding areas as it looks like an active one with open eyes and a straight body.
Why do ants sleep with their eyes open?
It is interesting to know ants do not close their eyes when sleeping, but it does not mean that their brain remains active all time as it also enters a resting phase.
State of alertness
Open eyes give a sense of alertness to insects like ants as they do not sleep for several hours. Instead, they prefer to have many short naps that last only for a minute or two.
According to our research, worker ants take almost 200 to 250 naps in a day after regular intervals, when each nap lasts only 50 to 60 seconds.
In contrast, queens sleep almost 80 to 90 times daily, lasting 5 to 7 minutes. This is because worker ants need more naps as they perform heavy-duty tasks compared to other ones.
Accordingly, they cannot enjoy deep sleep during naps as they enter a resting phase for a few seconds. Naps give a chance to relax their body muscles and brain for a short time, but their eyes remain open.
Absence of eyelids
The flaps of muscles and skin are usually present above and below the eyes of higher animals that act as mechanical barriers from foreign objects.
Eyelids restrict direct contact of sharp light rays and other air elements like air and moisture to the retina. However, it is not a characteristic of insects, as most of them lack muscular flaps.
Most commonly, insects have eyes, but they do not have eyelids and eyelashes like animals. This is because there are no flaps of skin to cover the retina.
So, you will find them enjoying naps with open eyes all the time, whether it is day or night time. In the same way, their retina is exposed to the environment whether they are sleeping or not.
Reduction in sensitivity
Ants enter a diapause and hibernation stage during winter when their metabolic process slows down or they begin to enjoy shallow or deep sleep.
These insects are not disturbed by environmental factors when they are in a deep sleep; even external stimulations cannot disturb them.
It rarely happens that these insects enter a diapause stage and remain inactive for a long time. Additionally, they cannot sense environmental and mechanical stimuli due to little activity.
It is observed that they can lose their muscle tone and sensitivity while taking longer naps, so their eyes remain open as they do not get disturbed by any movement in their surroundings.
Dryness of eyes
Higher animals have eyelids that help protect eyes from dirt and debris in the air and keep them moist.
Secretory glands are present in the muscular flaps releasing tears to wash out the foreign objects that can irritate. The fluid will dry out in the absence of these flaps posing a risk of infection.
Ants can keep their eyes open as they do not have lenses and contain compound eyes. Their retina folds in an outward direction that looks like a part of the exoskeleton.
So, their eyes are not a bag of fluids, and the exoskeleton covering makes them hard and dry, which avoids the need for blinking and washing out dirt.
Accordingly, they can easily sleep without blinking and washing to make them free of dust and other foreign objects.
Protection from invaders
Many insects and animals in the territory of ants try to invade these tiny insects and get food, but these remain active all the time, which makes it difficult to attack.
The predators will observe their behavior and look for the right time to attack and kill them. Closed eyes indicate the state of inactiveness that makes them prone to the attack of predators.
In addition, this behavior ensures their safety and improves their lifespan.
The invaders do not prefer to attack as they assume that these insects are in an active state and run away quickly when they attack.
Similarly, closed eyes pose a risk of death as invaders assume that they are sleeping, and it is easy to attack and kill them; that’s why they do not cover the retina.
How do ants sleep with their eyes open?
Almost all insects keep their open eyes during sleep as flaps of skin and muscles are involved in blinking behavior that are not present in them.
You can observe distinct postures in insects like butterflies and bees as they spend the night on different parts of plants, including stems and flowers.
Moreover, the sleeping butterflies will become insensitive to environmental changes as their eyes do not respond to surrounding images.
They cannot close their eyes and avoid curling their bodies like a ball, but you can see changes in the direction of an antenna during the resting phase.
These insects will remain in a single spot as their body movements get restricted when their brain is resting.
It is challenging to find a sleeping ant as you can get an idea by closed eyes and changes in body shape, but these insects do not cover their retina and remain straight.
However, you can observe antennal twitching behavior in sleeping ants and cockroaches. These antennal movements indicate that these insects are in a deep sleep.
In the same way, a few insects fold their antennae to protect their sensory organs, like olfactory receptors.
Do ants only sleep 8 minutes a day?
An ant takes around 200 to 250 naps in a day on average that last only less than a minute. It is estimated that all the day nap durations add up to almost 4 hours and 35 minutes.
Some researchers have observed the sleeping patterns of insects and found that ants follow a cyclical pattern, and each resting period lasts for 8 minutes in 12 hours.
A few people are amazed to know that these insects enjoy naps as they can see them walking all the time.
However, ant colonies have hundreds and thousands of members, and the active daytime group of workers enjoys sleep in the afternoon while the second group navigates surrounding areas.
So, these power naps ensure the colony’s survival, as there is a risk of attack when all insects enjoy naps.