Hantavirus or hantavirus pulmonary syndrome (HPS) is a virus contracted from rodents. With rodents starting to seek refuge inside, it’s something to be aware of. The Deer mouse is the primary carrier of the hantavirus in the United States but HPS can also be carried by cotton rats, rice rats and white-footed mice.

Since 2002 there have been over 300 known cases of HPS in California; unfortunately the virus proved fatal for almost 40%. As with many conditions, the prognosis of survival is much better when the virus is detected early on. HPS may stay dormant for one to five weeks before any symptoms appear; when the infected person starts to feel sick, the symptoms resemble those associated with the flu.

• Fatigue
• Muscle aches
• Fever
• Chills (only seen in about half the patients)
• Headaches (only seen in about half the patients)

After a period of up to 10 days, the infected person starts to develop respiratory problems including shortness of breath and/or coughing. At this point, it is imperative the infected person seeks medical attention.

As far as treatment goes, there is not a specific cure for the virus but oxygen therapy has been relatively successful in patients when the virus is diagnosed in the early stages. If you suspect hantavirus, be sure to tell your doctor you’ve been exposed to rodents.

HPS can be contracted through exposure to bedding, droppings, saliva or the urine. Aerosolization is one of the main ways to be exposed to HPS. In aerosolization, fine particles from the rodent (i.e. urine, droppings, saliva) carrying the virus are breathed in through the air; this provides an easy way for the virus to enter the body.

Because of aerosolization, it’s important to take some precautions when cleaning up after rodents. First off, do not sweep or vacuum the area. Completely soak the area in household cleaner or bleach mixture (1.5 cups of bleach with 1 gallon of water). After everything is wet, use a wet towel to pick up materials. Thoroughly disinfect the area again using a sponge and more household cleaner. Don’t forget to wear gloves and wash your hands after you remove the gloves.

Take care when cleaning up after rodents, and contact your local pest control company for some assistance if you’re concerned about exposure to HPS.

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}

Rats are some of the most destructive pests in the United States; parasite transmission and structural damage are just two results from a rat infestation. In California two species of rats cause the most problems, the roof rat and the Norway rat. Here we will talk about the roof rat.

First off, some history of the roof rat. The roof rat, also known as the black rat, is not indigenous to the United States; the species was brought overseas on ships and is known in history for carrying the bubonic plague.

What do roof rats looks like?

• Range in size from six to eight inches (not including the tail)
• Pointed muzzle
• A tail as long or longer than its body
• Black with a gray to white belly
• Ears long enough to cover each eye
• Smooth, sleek fur

Roof rats typically nest above the ground in attics, ceilings, crawl spaces, trees and need only 1/2” to enter a building. Because these rats are nocturnal and typically nest in higher places, the actual rats wont be seen often but there will be signs they are around. Some signs you have a rat infestation include, rat droppings, noises in the walls or ceilings, remnants or whole nests and of course rat carcasses.

Roof rats eat a variety of food but prefer nuts, fruits and insects but will also eat grain products and meat if they have to.

Preventing rodents from entering the building (don’t forget, eliminate their basic necessities including food, water and shelter) goes a long way but if you already find yourself with infestation you have a few options. Trapping and baiting are two strategies that have proved effective. Trapping is the safest, most effective and least expensive way to control rats indoors. Place traps in places where the rats are inclined to visit. If the rat population is out of control, the use of poisonous baits may be necessary but because of the risks involved, it is worthwhile to contact a licensed pest control company to control the rats.

Side note: Happy Thanksgiving from Southern California Pest Control Advice!

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.