You are out in the garage. You are doing a little cleaning up. All of a sudden you hear a strange noise behind you. It sounds like a little scurry, something brushing up against something. You turn around and you see a small tail scurrying under the old refrigerator. Oh my gosh, you think what was that, was it a rat, was it a mouse? How would I know if I could actually see it? Hi I'm Janice Creneti. I've been teaching animal and environmental science for about 20 years and I'm here to answer the question what's the difference between mice and rats. Well the short answer is not a lot. In a minute I'll give some specifics to help you identify which one is which. But first let's talk about what they have in common. You see both of them are mammals and they are also both rodents. They are small animals very important to the food chains in the ecosystems because they are food for a whole lot of predators that are out there. Because of that they tend to have very short gestation periods, that's the length of time they are pregnant and they also tend to produce a lot of babies, as many as a dozen every time they have a litter. They also can start having their own babies when they get to be about a month old so that is a lot of rats in a very short period of time, mice as well. Both mice and rats have to chew on things to get their big incisors, those are the front teeth that they have to gnaw on things. Well they actually have to chew pretty much constantly or those incisors can actually grow and puncture the roof of their mouth. Both rats and mice have caused pest problems in houses and in some cases they are considered invasive. They come over on shipments and colonized our country from different areas of the world. That can cause a problem because then they are used to being around people and they are used to getting into your houses and into your gardens and they can cause a lot of problems. Rats especially can be carriers of disease. So they have a lot in common. They are mammals, they are rodents and they can make a lot of babies in a very short period of time. But let's talk about how they are different so if you actually want to identify them you'll be able to tell. Let's talk about mice first of all. Mice are going to be much smaller than rats. Your adult mouse is only going to be a couple of ounces. It would easily fit in the palm of your hand if you are that brave. There is also a couple of things that you can look at on their bodies. Mice are going to have very rounded ears and if you actually look at their tail it will be covered in fur. Their noses don't tend to be quite as elongated. They're a little bit more round than what we see in a rat. Rats on the other hand tend to have a long pointy snout. You can really see it on this picture. The ears tend to be a little bit more elongated, not quite as furry. The tails are almost bald. I think that's part of what creeps people out so much about rats. Rats are going to be much larger. Some of the rats that would commonly get into your house, they can be close to a pound. The rats that you see living in the cities near garbage cans can even be much larger than that. Trust me if you are dealing with an adult rat you'll know that's what it is. I'm Janice Creneti and this is how to tell the difference between mice and rats.