• Chelle Hartzer

Caught in a Trap (AKA: We can’t go on together)

I get lots of requests for training and those are always catered to what the customer wants. It doesn’t do anyone any good if I give a presentation on ladybeetles and all they want to know about is cockroach control. With my customers controlling the training, I get to see patterns of what’s going on across the country, what may be increasing pest problems, and what people may be struggling with and want refresher training.


In light of many recent requests, today, let’s talk about rodent trapping.


I am an entomologist by training and certification, but I really enjoy talking about rodents. As someone in the pest control field, I’m not just an entomologist: pretty much any urban pest gets thrown my way and that’s exciting to me. Particularly rodents because our three main species (roof rat, Norway rat, and house mouse) are incredibly adept at infiltrating our abodes. And feeding off our foods. There are many risks associated with rodents including the general damage they do to structures and foods, also the diseases they can carry. Trapping rodents, especially once they enter a building is an effective way to eliminate them. Of course, like any pest control process, it has to be done correctly. Here are some considerations.

Against walls and edges is good

Right place

This can not be stated enough times: rodent traps need to be placed near to where the rodents are. This could be in established pathways, against wall/ground junctions, in elevated positions, near burrows/nests, or anywhere else the rodents have been observed. Putting traps away from the rodents is like putting a bag of chocolate chip cookies in my basement when I have Peppermint Patties right here in my office. I’m not going out of my way for the cookies, I’ve got plenty within arm’s reach. Rodents won’t go outside of their established runways and “home range” when they have everything there. So traps have to be put in those key areas so the rodents are intercepted in their own established areas. If you have roof rats, it’s best to put traps in the ceiling or on elevated areas, not on the ground where they won’t be.

Gnaw marks and droppings

If the rodents haven’t been observed, another good way to know where to place traps is to look for the secondary evidence. See where the droppings are, look for gnaw marks, displaced insulation where the rodents have kicked it out, or even the sebum (greasy marks) they leave as they traverse the same pathways.


Right time

Timing is key for a few reasons. We always want to prevent rodents from entering a structure (keep them outside where they belong!), but when they do get in, we want to intercept them as quickly as possible. So placing traps around openings they may use can quickly capture individuals. Timing is also important in placing traps because most often, traps are placed during the day. However, rodents are mostly nocturnal. Make sure to think about the nighttime conditions, particularly where lighting may be, can aid in trap placement. It means traps can be placed in shadowed areas where rodents are more likely to be.

SMALL amounts of food! Or they will eat it without setting off the trap.

Right food

There is lots of discussion about what food items traps should be baited with. Since our three main species will eat just about anything, almost anything is good to use! There are some that think you need to bait with something they are already eating. So in my case, it would be my Peppermint Patties. There is the alternate theory that you should bait with something they are not getting. So since I am getting lots of sweet, bait my traps with a protein like macadamia nuts. Personally, I think you should bait with everything. If rodents are indoors, using a single trap or a few traps is not going to be very successful or quick. LOTS of traps need to be used to catch the individuals quickly. With lots of traps being used, many different food sources can be placed on different traps. It increases the chance that the rodent will find something attractive.


I had an aircraft with a mouse on it once and we set out hundreds of traps. Literally, I think the total count was around 230 snap traps and glue boards. We used everything from gummy candy, chocolates, jerky, cotton balls soaked in vanilla, canned fish, jelly, and more.


I like the EZ Snaps from VM Products

Right device

I see this so often: TinCat style traps on each side of every door. Great, right? Sure…if mice are the problem, but if it’s rats, those are going to be worthless. The same happens with snap traps. If the issue is rats, you are going to need a bigger trap. Small, mouse-sized snap traps are not going to catch a rat. In fact, rats may set them off and learn to be “trap shy” and avoid any more traps that are put out. If snap traps are going to be used, I like to have them in a station whenever possible. The station is a nice dark space that rodents are more likely to go into. They like small, dark spaces. So putting traps inside a station makes them more effective. Plus, this protects the snap trap from being kicked, moved, accidentally set off, or more.


Maybe some adjustments here?

Right adjustments

Rodent traps and bait stations are often set out as a defensive measure, particularly for commercial accounts. When this happens, they tend to stay there and never get moved. However, the rodent pressures have changed, the weather has impacted populations, there may be construction, or any number of factors that impact where rodents may be. Rodent device placement should be evaluated at least yearly and changed if necessary.


That was a lot! But if pest control was easy, everyone would be doing it and we wouldn’t have pests. It’s not easy and the pests are always looking for ways to outwit the people trying to control them. If you want to know more about rodent trapping or how your rodent control program is doing, contact us here to see how we can help you.



Lagniappe - still one of the funniest "trapping" videos:





360 PFCS – your urban pest control consultants.

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