What Do Mice Like to Do? A Look at Their Daily Activities

Mice spend their waking hours on a remarkably varied schedule of nest building, foraging, exploring, socializing, grooming, and scent marking. Far from being simple creatures that eat and sleep, they have a rich behavioral repertoire shaped by millions of years of evolution. Most of their activity happens at night, and the way they divide their time reveals an animal that is constantly balancing curiosity against caution.

Active After Dark

Mice are nocturnal. Both wild house mice and common laboratory strains concentrate most of their activity during the dark phase of the day, with a sharp increase in movement at the onset of darkness. Lab strains tend to spread their activity across most of the night, while wild mice show a similar pattern but often drop off in activity a few hours before dawn. This basic rhythm means that if you have mice in your walls or as pets, the scurrying you hear at midnight is their version of the morning rush. During daylight hours, mice spend the bulk of their time sleeping and resting in their nests, waking only for brief bouts of eating or repositioning.

Nest Building and Burrowing

One of the first things a mouse does when given the chance is build a nest. Nest construction is an instinctive behavior seen across many species of mice, and it serves several purposes at once: maintaining body temperature, providing a safe place to rest, and creating a protected environment for raising young.¹ Mice are small animals with a high surface-area-to-volume ratio, which means they lose heat quickly. Standard room temperatures that feel comfortable to humans are actually on the cool side for mice, and researchers have found that mice adjust how much nesting material they use based on temperature, pulling in more material when conditions are cooler.² The quality of a mouse’s nest can even serve as a rough indicator of its general health and welfare.

Burrowing is equally important. When given access to digging substrate, laboratory mice readily construct burrows and continue to work for the opportunity even when it costs them increasing effort. Researchers have tested this using setups where a mouse had to perform more and more work to access digging material, and the mice kept at it, suggesting that burrowing is not just a casual preference but something closer to a behavioral need.³ In the wild, burrows provide protection from predators, insulation from weather, and a secure base for storing food. Burrowing patterns also have a strong heritable component, meaning the impulse and style of digging are partly written into a mouse’s genes.⁴

Foraging and Stashing Food

Mice are opportunistic omnivores, and a large chunk of their nightly activity goes toward finding and collecting food. In the wild, they eat seeds, grains, fruits, insects, and just about anything else they can get. But what makes mouse foraging behavior particularly interesting is hoarding. Mice routinely gather more food than they can eat in one sitting and transport it back to a secure location, typically in or near their nest or burrow. This creates a “larder” that serves as insurance against times when food is scarce or when a predator makes foraging too dangerous.⁵ If you have ever found a stash of pet food or seed behind an appliance, you have seen this behavior firsthand.

Foraging is not a reckless sprint to the nearest food source. Mice use established routes, rely on scent trails, and typically forage close to walls or covered pathways where they feel less exposed. They balance the energy reward of food against the risk of being caught in the open, and they adjust their behavior depending on how safe the environment feels.

Running for the Fun of It

You might assume that the running wheels common in pet cages are a human invention mice merely tolerate, but the evidence says otherwise. In an experiment where researchers placed running wheels in natural outdoor settings, wild mice voluntarily used them. Visits to the wheel continued even when no food reward was present, and the fraction of visits that included running actually increased when food was removed. This suggests that running on a wheel is something mice find rewarding in itself, independent of any foraging motivation.⁶ Frogs and slugs also used the wheels in that study, but mice were the most consistent visitors. The takeaway is that mice genuinely enjoy sustained physical activity, and providing opportunities for running is one of the more straightforward ways to support their welfare in captivity.

Exploring and Investigating New Things

Mice are intensely curious. When placed in a new environment, they launch into a structured pattern of exploration: venturing out, gathering information, and then retreating back to a familiar spot before heading out again. Research on rodent exploration has shown that mice and rats maximize new information during each outbound trip, retreating when novelty drops off and then exploring the next most unfamiliar area in sequence.⁷ Their whiskers play a central role during these investigations, sweeping back and forth to build a tactile picture of surfaces and objects.

Mice also have a strong preference for investigating objects that are new, changed, or moved. This is such a reliable trait that researchers use it as the basis for memory tests: a mouse that remembers a familiar object will spend more time sniffing a novel one placed beside it.⁸ Beyond simple novelty detection, mice show what looks like genuine curiosity about complexity. When given a choice between simple, smooth objects and irregular, complex ones, both male and female mice consistently spent more time investigating the complex objects, and increasing an object’s complexity led to even more time spent exploring it.⁹ Mice are not just checking whether something is dangerous; they seem drawn to stimuli that are informationally rich.

Communicating Through Scent and Sound

Mice live in a world dominated by smell, and they use urine-based scent marks as their primary communication system. A single urine mark carries a surprising amount of information: the species, sex, and individual identity of the marker, along with signals about social dominance, reproductive status, and health.¹⁰ Males are especially prolific markers, and the patterns change with context. Males deposit urine marks differently depending on whether the audience is a rival male or a potential mate, and the timing and intensity of marking shifts as social circumstances change.¹¹ After puberty, males ramp up scent marking substantially, and they can distinguish between the scent of different individuals even within highly inbred populations.¹²

Scent marking is closely tied to territoriality. A mouse patrolling its home range deposits urine marks along boundaries and in key locations, reinforcing its claim to the space and warning rivals. But marking is not only defensive. Males also use marks to attract mates, and the chemical signals in urine can convey information that influences social hierarchies without any direct confrontation.

Mice also vocalize, though most of their calls are ultrasonic and pitched far above what the human ear can detect. Young mice produce ultrasonic calls when separated from their mothers, and adults produce them during social interactions. Research on adolescent mice found that ultrasonic vocalizations were closely linked to social engagement: the more a mouse vocalized, the more socially interactive it was. Calls were also more frequent during mixed-sex encounters than same-sex ones, suggesting they play a role in courtship and mate assessment as well as general bonding.¹³

Grooming, Huddling, and Social Bonds

Self-grooming is one of the single most common behaviors you will observe in a mouse. It is an innate behavior with a highly structured sequence: mice typically start at the nose, move to the face, then the head, body, and finally the tail, following the same pattern almost every time.¹⁴ Beyond basic hygiene, self-grooming also functions as a stress response. A mouse that is anxious or unsettled often grooms intensely, and disruptions in normal grooming patterns can indicate neurological or emotional problems.

Mice also groom each other, a behavior called allogrooming. This social grooming is not random. Female mice, for instance, increase allogrooming toward cage mates that have experienced social stress. Research has found that this behavior depends on the oxytocin system: when the oxytocin receptor was knocked out in female mice, their grooming of stressed companions dropped sharply, while male mice were less affected by the same change.¹⁵ This hints at a form of social consolation that is more sophisticated than you might expect from a small rodent.

When facing a threat, mice huddle together. Huddling is not just about warmth; it also happens in response to predator cues. The social dynamics within a huddle can be complex, with dominant and subordinate mice jockeying for interior positions that offer more protection. Under predator threat, hormonal changes can increase huddling time and shift where individual mice end up in the cluster based on their social rank.¹⁶

Play Fighting in Young Mice

Play is well documented in rats, which wrestle and pin each other in elaborate bouts. Mice are less exuberant about it, but they do play. Young mice engage in a simplified version of play fighting that involves one mouse lunging toward the rump of a partner, apparently targeting the back of the neck as the ultimate goal. Nearly all of these playful attacks produce a defensive response: the target leaps, runs, or dodges sideways to avoid contact.¹⁷ What mice never do, interestingly, is wrestle. The defensive strategy is always evasion, never grappling. This means mouse play looks more like a game of tag than the full-contact wrestling seen in rats. Play makes up a small fraction of their overall social interaction, but it appears to follow the same basic attack-and-defend structure seen across many mammal species.

Pup Retrieval and Parental Care

When mice have pups, maternal behavior takes over a large portion of the daily routine. One of the most characteristic parental actions is pup retrieval: when a pup ends up outside the nest, the mother picks it up in her mouth and carries it back. This behavior involves a chain of sensory and motor responses triggered by cues from the pup, including its ultrasonic calls, warmth, and scent.¹⁸ Mothers also spend extended periods crouching over the litter to keep pups warm, licking them to stimulate digestion and elimination, and nursing. The nest that the mother built before giving birth becomes the center of operations, and she may spend a majority of the day inside it during the first week of her pups’ lives. Fathers in most house mouse populations do not provide direct care, but in certain species of deer mice and other relatives, paternal involvement is more common.

Assessing Danger Before Acting

For an animal near the bottom of many food chains, risk assessment is a constant background activity. Mice do not simply freeze or flee when they encounter something alarming; they perform a graded series of behaviors that researchers call “risk assessment.” These include stretching toward a suspicious stimulus while keeping the hind feet planted in a safe position, scanning the area with head movements, and making cautious approach-and-retreat loops before committing to crossing an exposed space.

Smell plays a big role in danger evaluation. Mice exposed to the scent of predators show heightened defensive behavior, and the response persists even after they have had time to habituate to the odor. Interestingly, a strong unfamiliar non-predator odor can produce nearly the same level of caution as a genuine predator scent, suggesting that novelty and intensity are themselves alarm signals that mice take seriously.¹⁹ This helps explain why mice are wary of new traps, bait stations, or any unfamiliar object placed along their usual routes. The initial suspicion has nothing to do with understanding what the object is and everything to do with the fact that it was not there yesterday.

How Wild Mice Differ From Lab Mice

Much of what we know about mouse behavior comes from laboratory studies, so it is worth noting that domestication has reshaped several key traits. Wild house mice are bolder about leaving a familiar area to explore their surroundings, and they do so faster than laboratory strains. They are also generally more active overall.²⁰ At the same time, wild mice are far more cautious in another way: they strongly avoid open, exposed spaces. Lab strains are more willing to walk through the middle of an open area, while wild mice hug walls and covered routes.²¹

This combination can seem contradictory until you consider the different pressures at play. Wild mice need to cover a lot of ground to find food and mates, so they venture out readily, but they also face real predators, so they avoid exposed situations whenever possible. Lab mice, bred for generations in predator-free cages, have lost some of that open-space wariness. Female wild mice show the same pattern: higher avoidance of exposed areas and more frequent rearing and scanning behavior compared to lab strains, consistent with a life where paying attention to your surroundings keeps you alive.²²

Gnawing and Object Manipulation

Mice are rodents, and the word “rodent” comes from the Latin for “to gnaw.” Their incisors grow continuously throughout their lives, so gnawing on hard materials is not vandalism but a biological requirement to keep those teeth at a manageable length. Mice chew on wood, plastic, cardboard, electrical wires, drywall, and anything else that offers resistance. In the wild, this means bark, roots, and seed shells. In a house, it means whatever is available, and it is one of the main reasons mice cause property damage.

Beyond dental maintenance, mice also manipulate objects with their paws while investigating them, turning items over and pulling at loose edges. This manipulation is part of the broader investigative behavior described earlier: mice do not just sniff new objects from a distance but actively engage with them physically, gathering tactile information alongside scent cues. Pet mice given enrichment items like toilet paper tubes, wooden blocks, or shredded paper will spend considerable time rearranging, shredding, and incorporating these materials into their nests, blending the lines between investigation, play, and construction.