A lot of people wonder about whether or not rats are nocturnal animals. Some folks want to know because they are thinking about getting a rat as a pet. Some folks want to know because they are hearing scratching sounds in their attic and are trying to figure out what animals have invaded their homes.
So, are rats nocturnal? Why do rats come out at night?
Yes, rats are nocturnal animals. They are very active at night. This applies to roof rats, Norway rats, and all species of pet rats. The primary reason that rats are nocturnal is that they have poor vision and only coming out in the dark puts them on an equal footing with their predators.
Rats Have Poor Vision
One of the reasons why do rats come out at night instead of during the day is that they have poor vision. According to the highly detailed report at RatBehavior.org, rats have extremely blurry visions (about 20/600), are red/green color blind, and are highly sensitive to changes in brightness.
Basically, rats are lousy at being able to see what predators are around them. By coming out at night, when it is already hard to see, the rats have leveled the playing field against all of the predators that want to eat them.
Instead of vision, rats rely upon, scent, touch, and memory to navigate. This is one reason that rats leave trails of poop and urine everywhere they go. Rats are not being nasty just for the sake of it but rather they are leaving trails to follow.
An example of rats using touch and memory to navigate is when they routinely follow the same paths by walking against the walls in your house. If you look closely you can find greasy “skid marks” on the floorboards of your walls. These skid marks happen when rats press themselves against your wall as a navigational aid and they follow the same path every night.
You can use their dependence upon touch and memory to your advantage when you are setting traps. If you spot a trail of rat poop or a greasy wall then you KNOW the rats will travel the exact same path again. Simply place the rat traps directly in the path that the rats are already using and your catch rate will go up dramatically!
Night Time Sounds in Your Attic
Back when I was dealing with my rat infestation the first indication I had of trouble was scratching sounds in my attic at night and right before dusk. I really wanted to believe that I was dealing with squirrels in the attic instead of rats. But it turns out that squirrels are active during the day and not at night.
If you are hearing attic noises at night or way early in the morning then chances are that you have rats.
I have to qualify that statement a little. I live on the Gulf Coast where roof rats (also called palm rats in Florida) are common and these things freaking love to get into attics. If you are in the northeast or sections of the country that have Norway rats instead of roof rats then those attic sounds are probably not rats. Norway rats are burrowing rats and don’t invade attics. For more information see Norway vs Roof Rats.
What Does It Mean If You See a Rat During the Day
If you are seeing rats during the day then something has happened that disturbed the animal. Rats are scared creatures that spend a large part of their brainpower figuring out how not to get eaten. Coming out during the middle of the day is not normal behavior.
The most likely scenario for spotting a rat during the day is that there is an overpopulation problem. The University of Massachusetts at Amherst suggests that for every rat that you see there are about another 25 present. When a rat nest gets too crowded the things will start attacking each other and at that point, the rat’s safest bet is to leave the den and find a new place to nest.
If you see rats running around during the day then chances are that you have a MASSIVE infestation on your hands!