An Insider’s Look at Trapping Urban Rodents

There’s more than one way to catch a rat, and when working in an urban environment, pest management professionals need to trap smarter. From bait options and trap placement to catching it all on film, “thinking outside the bait box” makes trapping more effective.

“There is very little virgin territory when you’re doing urban rat work,” said Timmy Madere, special projects coordinator, pest control specialist, New Orleans Mosquito, Rodent and Termite Control Board. “You always have to assume some pest management professional has been there before and they’ve tried traps, they’ve tried baits, they’ve tried everything.”

So to catch these conditioned rodents, Madere said that pest management professionals need to go in with a strategy.

“You’re basically shooting yourself in the foot a lot of times when you go out to a site and just start throwing stuff down immediately and not taking into account that these animals have been trained for generations of pest control guys going in there and going straight to the big guns when they should be taking their time and approaching it a little differently.”

BAIT OPTIONS. Although peanut butter is the go-to bait in the pest control industry, Madere suggests considering other options. Depending on the location of the infestation and the types of rodents, there may be better alternatives.

He said hazelnut spread, frosting, chocolate sauce, taffy and grape jelly can be sweet replacements in locations where people inside the building might be suffering from peanut allergies.

“Species to species, it’s going to be a little different, what bait you use for each,” said Madere.

Most species, especially roof rats, are interested in raw leaf spinach, cucumbers, apples, oranges, tomatoes, figs and bananas. He said that these wet baits are perfect for when it’s hot in the summer, or in a drop ceiling space where there is no water available.

Madere also suggests bacon bits, canned dog food, tuna, beef sticks, shrimp heads and spam as wetter baits, and sunflower seeds, birdseed and dried corn as dry bait.

The problem with these baits, are they do not only attract rodents. Small insects and cockroaches could be getting to the traps before the rats.

“If you’re going to use peanut butter, use crunchy, because if you get roaches and bugs feeding, at least they’re going to leave behind some of the nuts,” said Madere. “But sometimes we have to think a little bit differently with our bait options, because you’ll never catch a rat in an empty trap.”

To get around this issue, Madere uses cotton string soaked in vanilla extract, sesame seed oil, bacon grease or tuna juice.

The string is thick and easy to work with, plus it can be used on any trap, making it quick for prebaiting.

Female rodents are also interested in the string as a soft nesting material, but to get at it, they need to get up close and personal with the trap.

“Using string bait forces the rodent to interact with the trap more,” said Madere. “He has to get in there and actually go for the string. Their first instinct is to pull on it, and that’s going to set the trap off.”

But to get the desired effect — the string, or any other bait — must be positioned correctly on the trap, said Madere. Don’t crumple it and put it in the cup, or arrange it on the back of a Snap-E trap, and to prevent rodents from leaning over the trap to get a lick, try not to concentrate the bait on the back center of the trap.

TRAP PLACEMENT. Even if traps are baited with a rodent’s favorite bait, if they’re not set up in the correct location, the pests will never find them.

“When placing our traps, we need to look for run lines and shadows,” said Madere. “That’s where they’re going to go naturally, so why not put our traps there.”

He said to clean up before starting any trapping work — that way it’s easier to pick out fresh droppings, holes in walls or things rodents may have brought inside with them.

Are the rats running the pipes? Madere suggests Zip-tying the traps directly to them.

“It’s important where you place the Zip tie on the trap,” he said. “The trap has to stay stable so it doesn’t snap indiscriminately.”

He added that T-Rex traps aren’t great for pipes, because the rodent only has one access point, but there are other traps designed for this scenario, complete with predrilled Zip tie holes.

When placing traps on the ground it’s tempting to place a trap in the corner, but that means there are two less access points that the rat or mouse has to the trap. Instead, set up two traps on either side of the corner with the trip plate facing the wall to catch two.

Many times, more traps result in more sprung traps, but it is important to watch the proximity so each trap remains effective.

“Put your traps too close together and you’re working against yourself,” said Madere. “I’ve caught the same rat four times.”

When trapping outside, Madere suggests focusing on runs rather than burrows. Many rodents will end up jumping over a trap placed outside the burrow, but will collide head on with a trap on a path they run daily.

Trap placement can even accelerate the prebaiting process. Madere suggests setting up three traps next to each other, one prebaited on each end, and the one in the center set.

It’s also important to think about collecting the traps while you place them, said Madere. If a full trap falls down into a wall or an inaccessible corner of the attic, how will you empty it?

BAIT STATION BASICS. Madere’s first rule of bait stations is to always read the label first.

“The label is law,” he said. “Before I touch any kind of chemical, I want to know if it is going to hurt me, so I better read the label.”

Once the right amount and type of bait is established, it’s time to select the type of bait station and the bait that goes in it.

Mice like a lower profile box, while rats prefer something a little higher; however, if the box is too big, it could turn into a rat condo. They should come in, eat and leave, said Madere.

There should also be multiple bait types at each station. They need to be rebaited regularly, and the bait that hasn’t been touched needs to be removed.

Madere said that the rodenticide should match the bait. “Use odors to match the species to what it might want to eat.”

It is also beneficial to interchange rodenticide with non-active bait. “By using the non-active bait that also helps (the rodent) get over the fear of a food source and if it’s going to hurt them or not,” he said.

Once baited, each station should be placed with the entrance flush to the wall, creating a dark space that the rodents will want to investigate.

Madere suggests monitoring the boxes at least once a month depending on the site, because if the rats are not taking the bait, they could actually be nesting happy and healthy inside the box.

“In one or two months it could become a nightmare and something that actually makes your rodent problem worse for you,” he said.

He also said to place boxes only where you need them, because putting out boxes as a preventative measure could be welcoming new pests like American cockroaches while wasting time, money and bait.

BURROW BAITING. According to Madere, pest management professionals should use pellets exclusively for baiting burrows.

“House mice have little pouches and they love to make food hoards, little food stashes, and they will gather up those pellets,” he said. “If you’re a technician and you service houses and you use pellet bait, I almost guarantee you if you look in someone’s sock drawer you’ll find a stash of pellet bait.”

That pellet bait also looks like candy, which is dangerous to children.

Even when baiting burrows, it’s still important to be careful with pellets.

“I do a lot of it, but I also see a lot of it done incorrectly,” said Madere.

Before baiting the burrow Madere uses a flexible ruler to measure the distance inside.

“If I can’t get in a foot without it collapsing, I don’t bait that burrow,” he said. If he does bait the burrow, Madere uses a ½ inch or ¼ inch length of rubber tubing attached to a funnel to insert the pellets.

“Underbaiting and overbaiting are often an issue,” he said. “Be sure to read the label for the proper rate. Too little will not be effective, and too much will prevent the rats from even getting in the burrow — and once you put it in, you can’t take it out.

“It’s very much an art form. You have to be very delicate when you’re doing this, because you’re trying to be careful to not collapse the burrow, and burrows often have curves and hooks to them, so you’re feeling for that as you do it.”

When a burrow does collapse, the bait gets spread as the rodents dig out, making for a dangerous mess.

“What do you do in that situation?” Madere rhetorically asked. “You go and clean it up right away or you’re in some serious trouble. You don’t want to kill a non-target. That’s bad for our entire industry and it’s just sloppy in general.”

CAUGHT ON CAMERA. “If you’re in the industry and you’re working with rats, go out and pick up a few game cameras,” suggested Madere.

At about $85 apiece, these cameras open up a whole new world. Although it’s an art to get the lighting and focus just right, once it’s correct the infrared and black-and-white images and video can show a pest management professional exactly where the rodents are going and what they’re doing, said Madere.

“The cameras give you all kinds of really good information,” he said. The pictures can show were the rodents are eating and running, their patterns of activity and what they are doing with the bait.

According to Madere, pest management professionals should place cameras between three and six feet from the area they want to monitor, and should be aware of things like dripping water that could also trigger the shutter.

To adjust the lighting on the camera for the shorter distance, use duct tape on the flash, and if the pests are just too fast for the picture, try placing a brick in their normal path to slow them down.

Each of these strategies is just one piece of the trapping puzzle. To effectively end a rodent infestation, PMPs need to use resources like game cameras and location sweeps; stay up-to-date on the latest bait products; and have a thorough understanding of bait placement.

Time is money, but a little extra time at each site can result in a more successful trap, said Madere.

The author is a Cleveland, Ohio-based writer and can be reached at lstraub@gie.net.