From Dusk Till Dawn: How Guinea Pigs Perceive Darkness

You may have noticed that your guinea pigs seem awake most of the time, even at night. That’s because these little critters are active for 20 hours a day, and they sleep with their eyes open, which is a bit unsettling. But how well can they see in the dark, then? And how do they seem to know how to get around their enclosure at night?

Guinea pigs are crepuscular animals, so their eyesight isn’t well adapted for night vision. Instead, they rely more heavily on their other senses to navigate in the dark, e.g., smell, touch, and hearing. They also rely on memory to find their way around a familiar place.

As with any pet, understanding the behavior and physiology of cavies is essential for providing them with the best care possible. For instance, you might think you’re helping them by providing a night light. However, it’s advisable to refrain from doing so for their overall well-being. Read on to learn more about cavies’ visual capabilities as we shed light on their nocturnal vision.

How Well Can Guinea Pigs See In The Dark?

Guinea pigs are crepuscular animals, meaning they are most active during dawn and dusk. This means their vision is tailored to optimize their behavior during these periods. It also explains their inclination towards low-light conditions. However, before diving into their nocturnal vision, it is essential to understand the general visual abilities of cavies.

Basic Visual Abilities

While guinea pigs have a keen sense of smell and hearing, their vision is not as well developed. They are considered dichromats, possessing two types of cones that allow them to perceive colors in a limited spectrum.

Scientists believe that cavies can see colors in the blue and green range, but they might struggle to distinguish between red and green hues. This limitation is likely due to their adaptation to the environments in which they naturally thrive, e.g., landscape and food colors.

Adaptations for Nocturnal Vision

Although guinea pigs are not nocturnal animals, they exhibit a few characteristics that suggest a slight adaptation to dim light conditions. For example, one such feature is the large size of their eyes relative to their body, which enables them to collect more light and improve their sensitivity in low-light situations.

Other adaptations they have include their ability to sleep with their eyes open and the fact that their eyes are located on the sides of their head (they have a 340° vision range). While these adaptations could help with seeing in the dark, they are predominantly to detect predators.

The Role of Pupil Dilation

Like many other animals (and humans), guinea pigs rely on the dilation of their pupils to regulate the amount of light entering their eyes. For instance, in bright light conditions, their pupils contract to reduce the amount of light, protecting their sensitive retinas from potential damage.

Conversely, in dim light conditions, their pupils dilate to gather as much available light as possible. This mechanism helps them adjust their vision to varying light intensities during the crepuscular periods, i.e., dusk and dawn.

Lack of Tapetum Lucidum

While guinea pigs have a few adaptations for low-light conditions, they lack a well-developed tapetum lucidum, which is present in many nocturnal animals. The absence of this structure suggests that their vision is not optimized for complete darkness or moving around unfamiliar territory during the night.

That is why cavies’ visual system is better suited for low-light conditions rather than proper nocturnal activities.

Visual Behavior in Low-Light

Guinea pigs are descended from wild cavies in South America. In their natural habitat, wild cavies inhabit grasslands, savannas, and forest edges. It is during dawn and dusk that they become most active, foraging for food and engaging in social interactions. Additionally, they rely on their sense of smell, touch, and hearing to detect potential predators and locate food sources.

However, their vision does play a vital role in navigating their environment and identifying mates and group members.

Nocturnal Behavior of Domestic Guinea Pigs vs. Wild Cavies

It is essential to differentiate between the behavior of wild cavies and their domestic counterparts to understand how it can impact their vision. For instance, domestic guinea pigs (despite their descendants) have undergone changes in their behavior and physiology. These changes are attributed to human intervention, e.g., breeding, housing, and activity periods.

Therefore, while domestic piggies retain some crepuscular tendencies, their activity patterns can vary depending on their living conditions and interaction with humans.

The Role of Human Interaction

Despite being awake for 20 hours a day, domestic guinea pigs tend to adjust to their owners’ routines more than we might realize. For example, as pets, they tend to be most active during the day when their human caregivers are awake and interacting with them.

This shift in activity patterns could be attributed to their adaptability and reliance on their human companions for social interactions, food, and a sense of safety. That is why a domestic cavy will probably not fare well in the wild should it escape or be released.

Should You Illuminate Your Guinea Pig’s Enclosure At Night?

Speaking of safety, we know that guinea pigs are prey animals and, as such, tend to be skittish in the presence of strange people and other animals. So, you might wonder if you’d be making your piggy feel safer by illuminating its enclosure 24/7. However, this is not advisable, and you might cause your piggy more distress instead.

This is because guinea pigs, like humans and many animals, have innate circadian rhythms that regulate their sleep-wake cycles and activity levels. This means that artificial light sources – especially at night – can disrupt these rhythms and impact their behavior.

Light pollution, which refers to the excessive and artificial illumination of the environment, may lead to confusion in guinea pigs’ internal clocks, potentially affecting their overall well-being. Therefore, it would be better to refrain from adding a night light to your piggy’s enclosure. Instead, ensure it is secure and that no predators can enter the pen during the day or night.


Guinea pigs possess unique visual capabilities that are well-adapted to their crepuscular lifestyle. While they are not nocturnal animals, their visual adaptations enable them to thrive in low-light conditions during dawn and dusk. However, domesticated piggies tend to adapt to human interaction and may exhibit different activity patterns compared to their wild counterparts.