Yes, if you have a mouse infestation, or even just what you think are a few mice in your attic, there is a nest of baby mice. They reproduce very often, up to ten litters of young per year per female mouse, so they very likely have a nest of babies. The nest is a small round cavity, probably in the insulation of the house, maybe lined with leaves or other plant debris. When removing certain animals from attics, like raccoons or squirrels, it's important to seek out and remove the nest of young. With mice, these nests are very hard to find, and the young don't really have any chance of survival, so I don't make the finding and removal of baby mouse nests a part of my normal rodent control process. If you want to find and remove mouse nests, you are welcome to. You just have to search down in the insulation or walls where you see high levels of mouse activity. I have come across a few nests in my time as a wildlife removal expert, but they are usually well-concealed.
Here's a nest of baby mice. These are newborns, or maybe 1 day old at most. Many people refer to them at this size as "pinkies". These mice are often used as pet food for various snakes, birds, lizards, etc.
I actually don't know how to tell the age of baby mice. They grow so fast, and they are sexually mature at six weeks old! Other photos on the internet indicate that these little ones are likely 4 days old.
Finding mice in your attic means that you have a tough task ahead of you as you will need to figure out how they got into your attic, seal up their entry point, and remove all of the mice. To make matters more complicated, anytime there are mice in the attic, there are likely to be nests of baby mice as well. These rodents reproduce very quickly, making it almost a given that a nest of babies will be present.
Where Nests Are
In most cases, the nest of baby mice will be well hidden within your attic, perhaps tucked away behind insulation or down a little bit into a wall. If you know there is a mouse nest somewhere and can’t find it, you can listen or observe to discover its location. The mother mouse will visit the nest so you can watch her movements or just try to track them by looking for a trail of droppings or grease. You can also get rid of extra sounds and then listen for the telltale faint squeaking of the babies.
Hire A Professional
The easiest way to deal with a nest of baby mice is to hire a professional. They will be able to deal with the nest at the same time they take care of the adult mice in your attic. In most cases, the recommendation is to catch adult mice with snap traps since trapping and relocation rarely results in survival for these animals. Rodents are creatures of habit and putting them in an area they are unfamiliar with puts them at risk of predator attacks, dehydration, and starvation. Baby mice can complicate matters since the average homeowner will find it challenging to kill them humanely and snap traps won’t work if the mice aren’t moving around yet. Because of this, it is typically ideal to just have a wildlife removal professional deal with them for you as they will know the most humane methods to use.
Clean Up The Attic
After the baby mice and all adults in the attic are gone, it is time to clean up the area. Wear protective gear including gloves and a HEPA filter mask to prevent disease. Collect the nesting materials in a plastic bag and double bag it, sealing it tightly. Don’t forget to decontaminate the area with a strong enzymatic cleaner or at least bleach mixed with water. You will also need to prevent future animals in the attic by making home repairs and sealing up the entry points the mice used.