Integrated rodent management: use of mechanical traps

In the food industry, trying to control rodents with another food in the form of bait is challenging. Rodents have all possible alternatives in their nocturnal search for food. Why would they be interested in a new unknown food inside a device that is strange, new, and that was not in their last outing?

The burrow will be close to the food and water offerings, I would say from what I have seen, closer to the water source.

In the nocturnal route, they look for food, feed and return to the burrow, and for the most part they do so along paths already marked with smells, which are familiar to them, safe, so if the option of them eating bait is minimal or not allowed, it is time to use mechanical traps.

There are two possibilities. The well-known spring trap, with or without attraction, and the glue trap.

When I cannot, due to procedures or because it is not a valid alternative, use rodenticides, the option of mechanical traps is valid and useful.

The spring trap

The most important thing in the use of the devices is the location, the “where” I place the trap is the most important thing. I would say that the future of the operation depends on the location.

By recognizing the nocturnal movement and its paths, by the marks of grease, hair, footprints and excrement, we will know which is a familiar place for rodents.

If I am going to set spring traps, I suggest that they are not set the first night. Yes or yes, it is advisable to place them before the rodents begin to move and go out to feed, even more so if the temperature difference between day and night is very large, because if I leave it assembled at 20 degrees of temperature and it drops to 5, for example, it is most likely that it will be activated by itself due to the contraction of the metal.

When there is excrement, fresh or dry, it indicates that it is a place where the rodent feels safe and comfortable, and it is in this space where I should place the traps. It surely coincides with a corner or angle, and the best arrangement is against the wall, interspersing the device's trigger sensor, one towards the wall and the other in the opposite direction.

Let us remember that the traps should not be activated on the first night, since in the exploration that the rodents do during their journey, that first encounter with something new and unknown will make them avoid them and take precautions against that new element in the usual path or footprint.

The baited spring trap

Depending on what they have naturally available to eat, I must give them the option not available in the area. If the abundance is cereal, and dry foods or foods with little moisture, the best offer would be fresh fruit.

Another option that rarely fails is salami or pork belly, in small pieces, placed firmly inside the trigger. Wearing new disposable powder-free gloves, I take the trap and the salami or pancetta bait and rub it all over the device, finally placing the piece of bait on the trigger. With this we awaken the interest of the rodent that will approach, out of curiosity or because of the smell of the fatty bait, and activate the trap.

It is not necessary to use bait, but anything that increases the catch on those first nights of trapping is very important. Those first nights I can reduce the population to critical levels, if the location and number of devices is appropriate for the surface to be controlled.

Let's just think about the incredible reproductive capacity that rodents have. Each individual that is not caught is a basis for continuing the infection.

The amount varies, and depends largely on the available spaces, but a number that I consider useful and efficient is for every 30 square meters of angles, paths and paths, no less than 30 traps, that is, one trap per square meter of path.

The first three nights are the most important, and those with the greatest catch. How do I know if the capture is working? Relating it to the size of the population. Easy: first alpha males and alpha females will fall into the traps, then lower-ranking individuals. And when only juvenile individuals fall into the trap, I can say that part of the objective has been achieved.

From that point the most difficult part begins, which is to finish capturing the individuals in the colony, and for the most fearful rodents or those that had a close encounter with the trap to fall into the traps, escaped and now do not approach it.

The glue trap

To use glue traps I must consider the available space. Because it is a lower element, less than a centimeter thick, it enters places where the spring trap cannot.

The advantage of the glue is that it does not make noise, like the spring trigger does, which can scare away the rest of the rodents. If there is dust in suspension, I do not recommend them, because they must be replaced daily.

Curiosity, or carelessness in the direction, are the bases of glue trapping, as long as they are well placed.

Do not use any gluey products, only products intended for this purpose. They have no solvent, there is no recognizable smell, nothing that alerts them. The cardboard can be cut in the geometric shape that one needs, and the thickness is indistinct, trying not to reach the edge of the cardboard with the glue, so that if it flows it does not fall on surfaces, since it will be very difficult to remove it.

In the attempt to break free, more parts of the body become stuck. This lack of alert causes other individuals to join in the capture.

The disadvantage of using glue is the spills that can occur due to temperatures: the higher the temperature, the more fluid, and if the product falls from the cardboard it can cause damage to the surface due to the difficulty in removing it. The same thing happens if the temperatures are frigid: it hardens to the point that it may not be effective.

Pros and cons of mechanical traps

Advantages

• If they are strategically located, the population reduction is very rapid.
• You don't have to look for the corpses, as happens with baits: they are in the places where the devices were placed.
• I do not add more risk by having to place baits, in feedlots, indoors, during the emergency.

Disadvantages

• Requires daily review of devices.
• If rodents are trapped, after a few hours the ectoparasites leave the carcass, creating another problem.
• Specific PPE must be used to release the traps for the reason described above.