A couple weeks ago we mentioned the roof rat as one of California’s most common pest rodents, but there are others seen quite often including the Norway rat and the house mouse.

Rodents start to head indoors in early winter or when the temperatures start dropping; they move back outside in late spring. During this time of year, you may suspect a rodent infestation. Since rodents often move around at night when everything is quiet, it’s difficult to identify what rodent you have in your house, structure, etc… One of the best ways to properly identify your lurking creature is by taking a look at its droppings…yes, its poop.

Here’s a great visual of the differences between the three droppings.

House Mouse

House mouse droppings are the smallest of the three; their droppings are rod shaped, pointed at the ends and range between 1/8” and a 1/4” inch long.

Roof Rat

Droppings from roof rats are spindle shaped, curved and can reach about 1/4” to 1/2” in length.

Norway Rat

The droppings from the Norway rat are going to be the largest since the actual rodent is the largest out of the three. On average, Norway rat droppings are capsule shaped, vary between 1/2” to 3/4” in length and have blunt or rounded ends.

Fresh droppings can be a good indicator of a present rat infestation. Newer rodent feces are typically shiny and soft but after a few days the droppings will be dull, even grayish, and will become very brittle.

Note: Always use gloves and take precautions when inspecting or removing rodent droppings.

{photo credit (Norway rat): Losch}

{photo credit (roof rat): michaelpickard}

No one wants to invite pests into the home but unfortunately that’s often the case, especially with rodents. Mice may be cute to some but the effects of the rodent’s presence can actually be quite detrimental. Rodents including mice often cause physical damage to properties and structures and can even carry diseases including salmonellosis.

There are often obvious signs that mice are present; these signs include mice droppings, shredded paper, cardboard, etc… and gnaw marks.

According to the CDC, one of the best ways to prevent a rodent infestation is to seal up holes inside and outside the home. Some of the most common spots for gaps include around the fireplace, around pipes under sinks, attic vents and dryer vents. See the CDC’s site for preventing rodents to see an extensive list of common entrances.

To fix these gaps, fill the holes with steel wool and then caulk around the holes.  Don’t forget to seal garages and sheds too! It’s also beneficial to practice good sanitization when trying to prevent a rodent outbreak; mice are looking for food and shelter so avoid giving them what they need.

If you already have a rodent infestation, you can set baits or traps yourself. Traps are effective for a small number of mice or rodents but it is time consuming. Baits also work but take care because rat poison and rodent baits can be very toxic to pets and humans. But as always, call a professional exterminator when you are unsure or have more rodents then you know what to do with.