Your apartment location can affect how cockroaches, rats, and mice get in. A New York City exterminator told us the places he'd never live.

• Many US cities have major pest populations. About 15% of households in New York City report having rodent problems.
• While you can't completely avoid cockroaches, rats, and mice, some apartments are worse off than others, depending on their location in the building, proximity to parks, and age.
• We asked a professional exterminator from Top Notch Pest Control what to look out for and where in New York City he'd never want to live.

Following is a transcript of the video.

Larry Bernhardt: I walk into the apartment, I open the door, and immediately a smell hits you. Now, I can't really describe this smell, but it's very unpleasant. So now, I begin to just do your general just looking around. Then all of a sudden I'm like, it looks like the wall is moving. So, hundreds and hundreds of roaches on this guy's wall. That's just when you walk in. His mattress was completely infested with roaches. You could barely see that the mattress, the color of the mattress. I'll put it that way. It looked brown.

My name is Larry Bernhardt. I work for Top Notch Pest Control. I've been an exterminator for about 13 years now. Most pests will reproduce according to food, and, unfortunately, New York is severely overpopulated. So there's an abundance of food and shelter for them to just keep reproducing. You know, ton of rats.

Interviewer: Right.

Bernhardt: Rodents, roaches, you name it, it's pretty much in New York.

A few places I would never want to live is pretty much next to old, multi-unit buildings. So like your pre-war buildings. That's basically any building that was like built before World War II in New York City. There's a bunch of holes in the buildings. They're not up-to-date regulation-wise. Old piping, stuff like that, will always cause pest problems, a bunch of places for the rodents and pests to hide.

And, yes, next to a park because you don't know what's going on inside of the park with all the rodents. Rats tend to burrow, and if there's a bunch of ground that they can burrow into, they're gonna tend to nest there. Once they start looking for food, if there's not food ready for them, they're gonna make their way into buildings. Especially in the winter, they're looking for warmth. If your building is the closest to the park, you're gonna be the first place that they go.

So the worst floor to live on would actually be the ground level or first floor. Pests generally start to go from ground up, especially rodents. So you'll get your rat issues and your mouse issues from the ground up.

The pest problem is terrible near restaurants. It really has to do with the garbage, them disposing of it in the proper ways and also in, like, a timely manner. You know, a lot of these restaurants, they'll just have like a dumpster out in the back, and they're just putting the garbage right there. What happens is, after nighttime, the rats are just going to eat. So as they eat, they'll reproduce more.

And also with these takeout restaurants, if they are having a pest problem, and one actually has a roach egg in it, and now you're putting it into your cabinet, yes, you know have an infestation of roaches. I think most New Yorkers don't know that a roach egg will typically have 30 to 40 babies in it. So generally somebody sees one roach, they kill it, and they kind of move on with life. They don't realize that the first thing you should be doing is calling a professional or at least trying to take care of it on your own, that there's probably 30 more that you're just not seeing.

The most important things would actually be taking the trash out every night and making sure there's no dirty dishes in the sink. Also, no clutter. Clutter is the worst because once something gets in, you're not gonna be able to find it due to all the clutter and the messy conditions. You know, we're never gonna be ahead of it until people start taking sanitary matters very seriously.

I make my way into the bedroom, his mattress was completely infested with roaches. I've never seen that in all the years I've been doing pest control.

Interviewer: What does that mean, infested with roaches?

Bernhardt: You could barely see that the mattress, the color of the mattress. I'll put it that way. It looked brown.