Outdoor Pest Health Risks


As Californians experience a more complex and changing climate, there lies a persistent and growing problem – little pests. The California Governor’s Office of Emergency Services (Cal OES) wants to remind all residents of the Golden State to be vigilant when it comes to recreating outside. Sometimes the smallest threats can pose a significant health risk.

Some insects pose health risks due to the diseases they can transmit through skin contact or bites, and by contaminating food and water sources.

When recreating outdoors, it’s best to wear long sleeves, pants and use bug repellent on exposed skin and clothing to help prevent insect bites.

Changing Climate

There are a variety of potential factors statewide that can contribute to the abundance of pests or insects. California’s diverse climate, ranging from desert to temperate, provides the ideal conditions for various insects to thrive year-round.

  • As urban areas expand, human populations increasingly encroach on wildlife habitats, leading to more human-wildlife interactions.
  • International travel and trade contribute to the introduction of invasive pests and diseases, including bedbugs and new mosquito-borne illnesses.
  • Altered weather patterns and rising temperatures can expand the geographical range of pests and create favorable conditions for their increase.

In particular, the state experienced an intense storm season earlier this year, which not only led to high rains, but also significant snow melt and flooding. These abnormally wet areas then led to the proliferation of insects that thrived in these conditions.

Here is a partial list of the many bugs that can hurt you outdoors:


With recent wet conditions and warm weather, the California climate has created a breeding ground for mosquitoes. With more than 50 kinds of mosquitoes, not all are a threat to humans. But several that “bite” pose a threat to humans and can spread diseases such as West Nile Virus, Dengue, Malaria and more.

Learn more about Mosquito prevention


Wetter weather increased the growth of brush and shrubs, which are the home for several types of ticks that exist in California. In particular, ticks can often be found in areas with grass, shrubs, logs, large rocks or fallen leaves.

  • Western Blacklegged Tick: Can cause Lyme disease and anaplasmosis
  • Pacific Coast Tick: Can cause spotted fever and tularemia
  • American Dog Tick and Brown Dog Tick: Can cause spotted fever

A few tips:

  • If you see ticks on your clothing, its best to brush them off immediately. However, if you see them attached to your skin, remove it right away.
  • Use tweezers to grab the tick as close to the skin as possible, then pull the tick firmly, straight out and away from the skin, making sure to get all pieces of the bug removed (do not twist, burn or smother the tick).
  • Wash your hands and the bite areas with soap and water after the tick is removed, and apply antiseptic to the bite area.
  • See your doctor if you develop a rash or flu-like symptoms within 30 days after a tick bite.


Fleas thrive in many climates but prefer moist, humid, and shady areas. The area underneath a porch or deck can turn into an overwintering site. Areas with tall grass, leaf litter, weeds, wood piles, gravelly areas, and sandy patches are all attractive to fleas.

While most commonly found on small animals like rodents, opossums or strays, fleas can spread the bacteria that causes typhus. The symptoms associated may present themselves after 6 – 14 days after the bite and may present as fever, headaches, chills and muscle aches. Some cases may also present a rash on the chest and spread to the sides and back. Typhus is treated through antibiotics administered by healthcare providers.

To prevent fleas from entering the home it’s recommended to:

  • use flea control products on pets
  • keep pets indoors
  • do not leave pet food or trash outside that may attract animals
  • Seal holes and openings in the home where rodents can enter
  • Do not feed or try to touch stray or wild animals
  • Keep trash cans covered
  • Trim or remove plants near the house
  • Use insect repellent