A rodent is a gnawing mammal of a class called rodentia which is distinguished by a pair of constantly growing incisors in the lower and upper jaws. They are the most branched out mammalian class and live in different earth-bound habitats including man-made environments. The most widespread types of rodents are the rats, mice, guinea pigs, prairie dogs, beavers, porcupines, and squirrels. As much as they are used in laboratories and as food, rodents can cause negative effects. Due to the fact that mice and rats like areas that are bacteria utopias, if they are not identified earlier, they can create a big problem. They can cause sickness, and can introduce disease by carrying parasites. They have also been known to chew electric cables in homes causing fires. There are various ways of identifying rodents. However, most of them are identified by their traits. Some of these include:
Sounds- rodents produce sounds in different circumstances like:
- Due to their hard teeth, they tend to gnaw on hard surfaces to gain entry or to find food. As they do this, a sound like heavy scratching is produced. Also, as rodents search for new nesting places or forage for food, they produce a sound as they claw.
- Rodents produce sounds while communicating. For instance, rats have brilliant hearing and they often talk with each other using ultrasound frequencies we cannot hear. To us, they seem very silent, producing an infrequent squeak that is audible. But when they produce a sound at a high frequency that humans can hear, they may be stressed or frightened and using sound to protest discomfort or express pain.
Urine marking- A good example of a rodent that marks with its urine is the rat. It does this as a way of communicating with other rats. Marking helps rats determine where they are, and by following the musky scent trails they have left behind, rats can find out where they have been and what path to take to get back to their safe homes. The presence of urine can be detected by a UV black light.
Physical appearance- Although they resemble the lagomorphs, they have some unique features that distinguish them. They have a single pair of growing incisors both in the upper and the lower jaws. The outer surfaces of the incisors are surrounded by a double layer of enamel. They lack canines but have spade-shaped teeth located next to the incisors. They are small with robust bodies, short limbs, and long tails. They typically have four to five digits on each of the front feet and three to five digits on the hind feet. Usually, the sole is bare. The tail of some rodent species breaks off when they are caught by the tail, which allows them to escape. The tail will partially grow back.
Tracks- It is one of the most common signs of rodents. As they move, they leave tracks that are identified by the presence of their footprints. They have a plantigrade foot posture (walking with the entire sole of the foot on the ground). Due to their long tail, one can also observe their tracks by observing their tail drags. Rodents not only make footprints on dusty areas but also in moist or wet soil.
Droppings (pellets) – According to an article from Live Science, rodents tend to drop a lot mostly 40-50 pellets a day because of their small body size. The pellets slightly differ in size, shape and quantities. Most rodents like the mice tend to drop in a straight line. According to an article from Victorpest, a recent dropping is distinguished from an older dropping by its texture and coloration. It is softer in texture and darker in color than an older dropping. More droppings signify that the rodent population is high.
Gnawing marks- It is normal for rats to gnaw on wooden things like ceilings, door corners, and floor joints. Gnawing marks can be seen by:
- Holes and Burrows
- A mouse can create a hole size of a half inch in diameter with small clean cut edges but a rat’s hole is 2 inches in diameter with rough torn edges. Some rodents burrow on the ground in places like vines, bushes, trees or wood piles while others may burrow beneath a building’s slabs.
- Gnawed materials
- When rodents gnaw on materials, they leave back their remains. These materials include wires, plastic, wood, corners of cardboard boxes, bags and clothes.
Greasing marks- They have oily hair that is seen around beams, active runways, vertical surfaces, pipes, and rafters. These marks show that rodents had passed through that particular place.
Runways-These are the paths they use as they move. They are mostly between nesting areas and feeding areas. It is easier to notice grease marks along the runways because relying on their kinesthetic memory, they reuse the same path. Pathways are seen in dense vegetation, along walls, behind appliances or stored boxes and furniture.
Being the most diverse mammalian order, rodents have some common unique features that distinguish them from the other orders; for example, the presence of continuously growing incisors. However some traits like marking of their territories by urine and droppings are also exhibited by other mammals. By observing these particular common traits, one can identify and distinguish a rodent from other mammals.