So rats are known to be very clean animals. This often is something that people have a misconception about, but they generally take good care of themselves. They spend a large amount of the time grooming themselves, cleaning their faces, cleaning their paws, and overall keeping their skin and coat in excellent condition. They don't require trips to the groomer if you were concerned about that, but there is some basic maintenance they may need.
Most often people will need to trim their nails if their nails become very sharp. If they have a pet rat that's very social, that likes to climb on them, that enjoys being held, especially if it's one of the types of rats that loves to sit on the shoulder or loves to be around and climb on people, you may find that their nails become sharp and it becomes important sometimes to trim them. What's important to realize is that they don't have very long nails. So the ability to trim them often means cutting off the tiniest little tip of the nail or it requires filing them or using a dremel type tool with a burring tip to just take the points off. Most commonly if I have a rat in the hospital and it needs its nails trimmed, basically we'll use a low speed dremel, and we'll just touch it to the nail so that we can just take the tips off of the nails. If somebody is going to try to cut the rat's nails they're going to have to use a very sharp, very small nail trimmer and a human nail trimmer works fine including the type made for infants or toddlers, works fine to just take the very tip of the nail off.
They don't need a lot of other routine grooming. Some people will attempt to brush their pet rats. They may or may not tolerate brushing but at least it's a means of collecting some of their hair and on rare occasions, people will bathe their rats. In general, rats may or may not like being in a bath or being in the water. Some of them take to it very well and enjoy it. Others don't like to be in the bath and don't like the whole sensation of being lathered and wet and rinsed. So it's not vitally important unless it's medically necessary or unless they become excessively dirty for some reason, that they are going to need routine bathing or any other type of routing grooming. Some of the breeds of rats may need occasional bath just if, like I said, they become particularly soiled for some reason, there's an accident in their cage or something happens and that becomes necessary. But otherwise, routine grooming in pet rats generally involves keeping their nails trimmed as needed and making sure they are taking care of themselves as well.