Rats are not a specific species but a common name for a collection of species. There are many different kinds of rats and some of them are very large and some of them are very small. Roof rats, or ship rats and very small and tend to be very good climbers who can scale a drainpipe with ease. The most common rat you will likely come across is called the street rat or the common rat, in truth, it is the Norway rat and came here from Europe. The fact that it is from a different continent makes it especially dangerous as it has no specific predators here. While they can be predated by local animals and birds they are different in how they function and have managed to breed and take over entire cities, seemingly unstoppable in its destruction. Rats in New York City are the cause of billions of dollars in damage per year in both wasted food and damage to property. They are tenacious and they seem fearless of humans. Unlike other rat species, they will not necessarily run away when they see a human.
If you are dealing with a rat infestation or have suspicions thereof, contact Rat Pest Control for a fast and effective complete eradication.
Now if you have small rats they are likely not in the house but the attic. The roof rat is quite small, and often mistaken for a mouse but it is most definitely a rat. The types of mice that will invade an attic are deer mice and field mice, field mice and roof rats could be mistaken for each other by an untrained eye. Now if you have them in your attic it is a good idea not to go into the attic, you are not an exterminator and are not prepared for the possibility of airborne pathogens and the smell can be very strong. What more, a rat may take your entry as a threat and if there are a lot of rats in the attic, they may try to harm you with their bite which can be extremely painful and dangerous as you could get sepsis in the wound.
The best thing to do is to call in a professional exterminator with experience and constantly updated training to come to the house and do a full inspection to seal entryways the rats are using to get in and to install snap traps and external bait stations to kill the rat population not just in your attic, but the one in the back yard as well.