Rat Proofing 101

It is not uncommon in San Diego for homeowners, as they are enjoying a balmy twilight on their patio, to see the shadows of furry creatures skittering along fence lines. Trouble in paradise! Rodents are out there, living perhaps in your neighbor's bougainvillea or in the canyon behind your house. With colder nights coming soon, now is the time to secure your house against these critters. 

Roof Rats are the most common home invader in San Diego. They are excellent climbers, often living above ground in trees or in dense ground cover, like ivy. If you see rat droppings around pet dishes or hear noises in the attic at night, chances are good these are evidence of roof rats. The first element of successful rat management is sanitation. Check to be sure lids fit tightly on garbage cans, and if you feed your pet outdoors leave only as much food as the pet will eat at a feeding. Better yet, feed them indoors. To rodent proof your home, check all vents - attic, sub floor, clothes dryer, and rooftop plumbing vents, to be sure they are properly and securely screened. Seal any openings around pipes or cables that go into the house. Cover the chimney with a spark arrester. Repair or replace weather stripping on exterior doors, including garage doors. Check window screens to assure they are in good condition. Trim tree branches and vines away from the house. Since rats are such agile climbers, they often enter attics by climbing trees next to the house. If you have fruit trees, pick the fruit as it ripens - do not let it fall to the ground, where it becomes an attractive nuisance. 

The Vector Control Program here in San Diego County will do a free inspection of the outside of your home upon request. If you have seen evidence of rats on the property, call them at 858-694-2888 or send an email request to vector@sdcounty.ca.gov. They also offer a "Rat Control Starter Kit," which contains a bait station, some rat traps, sample hardware cloth, a DVD and a brochure. Visit their site here  to find out more. Vector Control is quick to point out they are not a pest control service - so if you need professional help beyond what they can give you, call us here at Centurion.

Although many of the exclusion methods outlined here apply equally to mice, these smaller rodents can squeeze through even tinier openings, often fitting through a hole the size of the diameter of a pencil! So even more care is required in mouse proofing your environment. We'll discuss control of the very common house mouse in tomorrow's blog. 

Rodent Quiz Answers

Here are the answers to yesterday's Rodent Quiz. How did you do? Hopefully the answers will help you protect your home against these unwelcome visitors.

1. Rats have poor eyesight, but they make up for this with keen senses of smell, touch, hearing, and even taste. For this reason, when we set traps they are best placed next to a wall - preferably a wall the target rodent is familiar with. Sometimes the traps are not sprung for a few days, as rats are naturally cautious of any new and unfamiliar object or odor. So the answer is (d) - all of the above.

2. Rats can squeeze through an opening as small as (b) 1/2 inch. Keep this in mind as you look for ways to rat-proof your home. An opening the size of a half dollar can be a thoroughfare for rats. And if rats can fit through a 1/2-inch opening, mice can access a much smaller breech. Check the weather stripping on all your doors!

3. According the the San Diego County web page on rat control, a typical rat will travel up to(c) 300 feet to find food. Think football field. They may live in your neighbor's shrubs and eat at your house. For this reason alone it is a good idea to keep pet food indoors.

4. The best protection against rodent infestation is (c) exclusion. The more proactive homeowners are in sealing and screening vents, doors, and other openings that may invite rodents, the less likely they are to have to do any trapping or baiting.

5. Plague is not a historical disease. And it is not the only disease rats may carry into your home. Among other diseases rats may transmit to humans or pets are, leptospirosis, trichinosis, salmonellosis and ratbite fever. According to PCT online magazine, there are (b) 10-15 cases of plague per year in the United State directly related to rodent exposure.

6. The tendency of rats to avoid anything new in their environment is called (a) neophobia. Answer (d), "zenophobia" is a misspelling of "xenophobia," a related human fear of strangers. The other answers are ringers. Neophobia is peculiar to rats. Mice are much more inquisitive.

7. (D) Rodents are always seeking nesting material. Placing a piece of dental floss or string on the treadle of a snap trap has been found to enhance the likelihood of successful trapping.

8. As noted in the answer to #6 above, mice are naturally  more inquisitive than rats (d). Although both are rodents, it is helpful to know some of the basic differences as we try to protect our homes against rodent invaders. As is so often true in pest management, an ounce of prevention is worth a pound of cure. Tomorrow's blog will give more suggestions for rodent-proofing  your house, along with information on free county services.

Rodent Quiz

Here is a timely quiz, not just because it is the Year of the Rat, according the the Chinese calendar, but because we are at the end of summer here in San Diego. As the nights get colder, rodents look for harborage indoors. The more you know about rodent habits, the less likely you are to find them harboring with you. The answers to today's quiz will appear in tomorrow's blog.

1. Rats make up for their poor eyesight with a keen sense of

a. smell

b. touch

c. hearing

d. all of the above

2. Rodents can squeeze through small openings. How small an opening can a rat fit through?

a. 1/4 inch

b. 1/2 inch

c. 1 inch

d. 2 inches

3. About how far does the average rat travel to find food?

a. 50 feet

b. 50 yards

c. 300 feet

d. 300 yards

4. The best protection against rodent infestation is

a. baiting

b. trapping

c. exclusion

d. electric fences

5. Plague is a rodent-borne disease. How many cases of plague are reported each year in the United States?

a. 1-2

b. 10-15

c. 20-30

d. 50-100

6. Rats are naturally wary of new objects or odors. This behavior is called

a. neophobia

b. odophobia

c. zenophobia

d. exophobia

7. Placing a piece of dental floss on the treadle of a snap trap may be effective because:

a. mice practice impeccable dental hygiene.

b. mice are compulsive collectors of odd items

c. the dental floss gives off a scent which is pleasing to rodents

d. rodents are always seeking nesting materials

8. One difference in the habits of rats and mice is that

a. rats carry fleas, but mice don't

b. mice will not infest a home

c. rats love peanut butter

d. mice are more inquisitive than rats

Again, most of the answers are easily Googled. Try to answer without help. Answers appear tomorrow.