If you’ve ever seen a rat in your house, it was probably at night. Rats seem to know exactly when to come out, and they’re really good at avoiding you during the day.
You might wonder how they always seem to be active when you’re asleep and how they know when it’s safe to leave their hiding spots. So how do rats know when to come out?
Rats know when to come out by using their internal body clock and by sensing changes in light, sound, and activity levels in their environment. Rats are naturally active at night (nocturnal), and they come out when it’s dark and quiet because that’s when they feel safest from predators.
Rats have developed this nighttime behavior over thousands of years because it helps them survive. Understanding how rats decide when to come out can help you deal with them more effectively.
Rats Are Naturally Nocturnal Animals
Rats are nocturnal, which means they’re programmed to be active at night and sleep during the day. This isn’t just a habit, it’s built into their biology.
In the wild, being active at night helps rats avoid predators that hunt during the day like hawks, eagles, and other birds of prey. By coming out at night, rats have a better chance of finding food without getting eaten.
Rats have an internal clock (called a circadian rhythm) that tells their body when to be active and when to rest. This clock is controlled by changes in light.
When it gets dark, a rat’s body starts producing hormones that wake it up and make it more alert. When it gets light, different hormones tell the rat’s body it’s time to sleep.
This is why you’ll almost always see rats at night, not during the day. Their bodies are literally wired to be awake when it’s dark.
Even if a rat is living in your house where the light doesn’t change much (like in a dark basement), it’ll still follow this natural pattern pretty closely.
How Rats Sense Light And Darkness
Rats have pretty good vision, but they’re especially sensitive to changes in light levels. Their eyes are designed to work well in low light, which helps them see at night.
When the sun goes down and your house gets darker, rats can sense this change. Even if you have lights on in some rooms, rats can tell the difference between daytime light and nighttime light.
Natural sunlight is much brighter than indoor lighting. When natural sunlight fades, rats know it’s getting closer to their active time.
Rats living in places without windows (like inside your walls or in a basement with no windows) rely more on other signals like sound and vibrations. But if they have any access to natural light at all, they’ll use it to help them know when it’s nighttime.
Sound And Activity Levels Matter
Rats aren’t just waiting for darkness, they’re also listening to what’s going on around them. During the day, your house is probably full of activity and noise.
People are walking around, talking, moving furniture, running appliances, and making all kinds of sounds. All this noise and movement tells rats “humans are active right now, so it’s not safe to come out.”
Rats can hear really well, much better than humans actually. They can hear sounds at frequencies we can’t even detect.
When they’re hiding in their nests, they’re constantly listening to what’s happening in the house. They learn your routine pretty quickly.
They know when you wake up, when you leave for work, when you come home, and when you go to bed. As the house gets quieter at night and people stop moving around, rats know it’s their time.
This is when they feel safe enough to come out and look for food. If you work night shifts and you’re active in your house at night instead of during the day, rats will adjust their schedule.
They might start coming out during the day when you’re asleep instead. Rats are flexible and will change their behavior based on when they think it’s safest.
Rats Learn Your Schedule
Rats are actually pretty smart. After living in your house for even just a few days, they start to figure out your patterns.
They notice when you turn lights on and off, when you’re in different rooms, and when everyone goes to bed. They use this information to decide the best times to come out.
If you always go to bed at 10 PM, rats will learn that after 10 PM, the house gets quiet and safe. They’ll start coming out around that time every night.
If you get up at 6 AM every morning, rats will learn to go back into hiding before 6 AM. This is why you might never see rats even if you have a big infestation.
They’ve learned your schedule so well that they’re always active when you’re not around. Rats also remember which rooms are used most often and which ones are quieter.
If you rarely go into your basement or attic, rats will feel much safer being active in those areas even during odd hours. But in your kitchen where you’re in and out all day, rats will be much more careful and will usually only come out late at night.
Temperature And Weather Affect Rat Activity
Temperature plays a role in when rats come out too. Rats prefer moderate temperatures, not too hot and not too cold.
During really hot summer days, rats might wait until evening not just because it’s dark, but because it’s cooler. The heat during the day can be uncomfortable for them.
In winter, rats might come out earlier in the evening or stay out longer in the morning because they’re trying to find warm spots and food. Cold weather makes rats more desperate, so they might take more risks.
Rain and storms can also affect when rats are active. During heavy rain, rats might stay in their nests instead of coming out to look for food.
But right after a storm passes, they might come out at unusual times because they’re hungry and need to find food they missed. If you notice rats coming out at weird times, check if there’s been recent changes in weather that might have messed up their normal schedule.
Hunger Drives Rats Out
While rats prefer to come out at night, hunger can make them break this rule. If a rat is really hungry or if food has been hard to find, it might take the risk of coming out during the day.
This is especially true if the rat has found a food source that’s only available at certain times. For example, if you feed your dog at noon every day and there are always crumbs on the floor afterward, a really hungry rat might come out during the day to get those crumbs.
Rats need to eat constantly. They can’t go more than a few days without food before they start to weaken.
If they’re not finding enough food during their normal nighttime activity, they’ll start coming out at other times. Seeing rats during the day is often a sign of a really big infestation.
If there are so many rats competing for food that some can’t get enough at night, those rats will be forced to come out during the day even though it’s riskier.
How Rats Use Their Other Senses
Besides vision and hearing, rats rely heavily on their sense of smell and their whiskers to know when it’s safe to come out. Rats use their whiskers to feel vibrations in the air and to help them move around in the dark.
When you’re walking around your house, rats can feel those vibrations through the floor and walls. When the vibrations stop (because everyone’s asleep), rats know it’s safer to move.
Their sense of smell is incredibly strong too. They can smell food from far away, and they can also smell other rats’ scent markers.
If a rat smells fresh human scent in an area, it’ll be more cautious about going there. But if an area hasn’t been used by humans in a while, rats will feel more comfortable being active there.
This is why rats love attics, basements, and storage areas that people don’t visit often. The lack of fresh human scent tells rats it’s a safe zone.
Different Types Of Rats Have Different Patterns
While most rats are nocturnal, there are some differences between species. Norway rats (also called brown rats or sewer rats) are strongly nocturnal and rarely come out during the day unless conditions force them to.
Roof rats (also called black rats) are also nocturnal but can sometimes be active around dusk and dawn. These “twilight” periods are called crepuscular activity.
If you have roof rats, you might see them a bit earlier in the evening than you would see Norway rats. But both types follow the same basic pattern of being most active when humans are least active.
What Happens If Rats Are Disturbed During The Day
If you accidentally disturb a rat during the day, you’ll probably see it run back to its hiding spot really quickly. Rats feel vulnerable and exposed during daylight hours.
Their instinct is to get back to safety as fast as possible. If a rat’s nest is disturbed during the day (like if you move boxes in your basement where rats are nesting), you might see several rats scatter in different directions.
They’ll all be trying to find the nearest dark, quiet place to hide until night comes again. Disturbing rats during the day can actually be useful if you’re trying to get rid of them.
It messes up their sense of safety and makes them stressed. If you make noise in areas where rats are hiding, play a radio, or turn lights on and off at random times, rats will feel less secure.
This won’t make them leave on its own, but it can make them more likely to move into traps or to leave if you’ve sealed off their entry points and removed food sources.
Do Rats Come Out Every Night
Not every rat comes out every single night. Rats take turns going out to find food while others stay back to guard the nest or care for babies.
If a rat found a lot of food one night, it might not need to come out the next night. Rats also fast sometimes, which means they’ll eat a big meal and then rest for a day or two.
Younger, bolder rats tend to come out more often than older, more cautious rats. If you’re seeing the same rat every night in the same spot, it’s probably a young male that’s exploring and establishing its own territory.
Female rats with babies might come out less often because they’re busy nursing and caring for their young. But when they do come out, they need to find enough food to support both themselves and their babies.
Signs That Rats Are Active In Your House
Even if you never see a rat, there are signs that tell you when they’re active. Fresh droppings are the biggest clue.
If you find droppings that are dark and moist, rats were there recently (probably the night before). Sounds are another sign.
If you hear scratching, scurrying, or squeaking in your walls or ceiling at night, that’s rats being active. Listen between 10 PM and 4 AM, which is when rats are usually most active.
You might also notice food that’s been chewed on or packaging that’s been torn open. If you leave food out overnight and it’s been disturbed by morning, rats came out during the night to get it.
Greasy rub marks on walls are another sign. Rats have oily fur, and when they run along the same paths repeatedly, they leave dark smudge marks.
If you see these marks, rats are actively using those routes, probably every night.
How To Catch Rats Based On Their Schedule
Knowing when rats come out helps you catch them more effectively. Set your traps in the evening before rats become active.
Place them along walls, behind appliances, and in areas where you’ve seen signs of rat activity. Rats start coming out around dusk and are most active in the middle of the night.
By setting traps in the evening, they’ll be ready and waiting when rats start moving around. Check your traps first thing in the morning.
If a trap caught a rat during the night, you’ll want to remove it quickly and reset the trap for the next night. Don’t leave dead rats in traps for long because the smell can warn other rats to avoid that area.
Some people try to catch rats during the day by making noise and disturbing them, but this usually doesn’t work well. Rats will just hide and wait for you to leave.
It’s much more effective to let rats come out on their own schedule and catch them with well-placed traps.
Conclusion
Rats know when to come out by using their internal body clock, sensing changes in light, listening to sound levels, and learning your daily routine. They’re naturally programmed to be active at night when it’s dark and quiet because that’s when they feel safest.
Rats are constantly monitoring their environment, listening for human activity, and waiting for the right time to come out and look for food. Understanding their schedule helps you know when to set traps and when to expect activity.
Most rats will come out between dusk and dawn, with peak activity in the middle of the night. If you’re seeing rats during the day, it usually means the infestation is pretty bad and rats are being forced to come out at risky times because of hunger or overcrowding.
The best way to deal with rats is to work with their schedule, not against it. Set traps at night when they’re active, and take away the things that make them feel safe coming out (like food, water, and easy hiding spots).
Hi, my name is Ezra Mushala, i have been interested animals all my life. I am the main author and editor here at snakeinformer.com.