Roof Rats San Diego – What to Do When You Find Rodents in Your Attic

To rodent proof your San Diego home, and guard against pesky roof rats, it helps to get a better understanding of the problem. This is our in-depth guide to dealing with unwanted rodent roomates.

Roof Rats: A few facts and figures

Rattus rattus is the Latin word scientifically given to the species of rat commonly identified as roof rats. also known as ship rats, Alexandrian rats, and most notoriously, black rats. An abundant supply of nourishment along with an ill-lit area provides the perfect conditions for inviting in a whole host of these unwanted guests. Attics, false ceilings and hollow wall openings (crawl spaces) attract them the most because these nocturnal creatures prefer to stay hidden and out of view.

The most detrimental aspect of these pesky animals is the fact that they have been historically known to carry deadly diseases – including the bubonic plague. Nowadays, they transmit diseases by contaminating our food and water supplies. Additionally, rat bites and even flea bites from fleas which have bitten infected rats beforehand are known sources of disease transmission. Besides fleas, a number of other parasitic insects transmit diseases indirectly from rats to humans.

Here are a few of the distinguishing features of Roof Rats:

  • They are nocturnal animals and rarely emerge during the day.
  • The upper level of your home is their favorite breeding ground.
  • They are known to be omnivorous but prefer a vegetarian diet.
  • A quarter size opening is all they need to invade your premises.
  • The Nests they create can pose a substantial threat to building foundations.
  • Roof rats are known lovers of fresh citrus fruits such as oranges and nectarines.
  • They have been known to chew through and compromise electric wiring, plastic, and lead pipes.
  • They mate and breed all year long have a gestation period of 21 days where they have about 7 pups per litter the litter will be at breeding age within 3 months.
  • Before moving into human structures they were primarily arboreal (living in tress), which helps to account for their ability to move swiftly along power cables, vines, and roofs.


You can easily identify a roof rat from a Norway rat or house mice by its peculiar features; a muzzle pointed nose, scaly tail longer than their bodies, brownish gray to dark brown complexion, smooth fur and large ears.

Is San Diego infested with roof rats?

Out of all the categories of rats roaming around, roof rats are the most frequently found species in San Diego County. Southern California in general, but specifically San Diego, is a hotbed for roof rat activity. In fact, scientists have concluded through the analysis of many studies that rattus rattus colonies thrive within 100 miles of coastal areas. There have even been a few documented instances of roof rat colonies flourishing well beyond this threshold limit.

The coastal vegetation dotting San Diego is the paramount reason for rodent’s overpopulated existence in this area. In short, it is an ideal breeding ground for many species of rats, and specifically roof rats, because they feed on this vegetation. Their primary target is the regions orange and pomegranate farms.

See Also: How to Rodent Proof Your Attic Insulation

How would I know if roof rats are already inside my home?

If you hear strange noises such as scratching, gnawing, and scraping coming from the walls at night, chances are it’s not your imagination. The easiest way to confirm an infestation is to sweep the suspected area in search of the long cylindrical droppings of roof rats and the distinct smell of their urine. Yet another method is to look out for half-eaten citrus fruits in your garden or backyard, because as mentioned earlier, these are their favorite snacks.

If you have a dog or a cat at home then they too can become your secret agents in locating these creepy rodents. This is because pets tend to vigorously sniff around the vicinity of an infestation. If your animal is constantly whiffing around a suspicious area in your home, it may be time to check for an invasion.

Follow These Simple Steps to Block Roof Rats from Entering Your Home

  • Never leave fallen citrus in your garden.
  • Do not keep large wood or brush piles in your yard.
  • Use chimney caps to prevent entry via your fireplace.
  • Seal off every crevice in your home down to the size of a nickel.
  • Keep any palm trees well-groomed as they are a known attractant of these rodents.
  • Keep food out of their reach and ensure that there is no pet food for them to nibble upon.
  • Make sure that your pets entry doors and screens are sealed and secured before going to bed.
  • Regularly prune shrubs and trees in your yard to a minimum height so their base is observable.

If you implement these simple yet crucial steps to safeguarding your home, I can assure you that these dark brown nuisances will not succeed in gaining entry and establishing a colony.

How to eradicate roof rats from your home.

The most obvious way to eradicate a colony of roof rats is to entrap or dispose of the roof rats who have gained entry into your house. Attic Construction provides attic cleaning, insulation installation ,Β insulation removal and replacement, and rodent proofing.

Why you should take against roof rats action now.

If you think you have a roof rat problem it is advised that you take immediate action. Oftentimes people simply ignore an infestation until it becomes too big to handle. If you let the conditions dissolve to that point, then you may end up spending several times what you would have spent to alleviate the problem had you had acted swiftly. Waiting to solve your rodent problem will only increase the damage and cost associated with early prevention and elimination.

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