What Are the Most Common Pests in Pasadena?
Posted by Mosquito Squad Plus
June 1, 2026
Year-round warmth, mild climate, and beautiful landscaping are all ways to describe Pasadena. You live here because the warmth, sun, and vibe allow you to be your best self. You thrive here.
But guess who else thrives here? Pests. Of all kinds.
Pests love Pasadena for all the same reasons you do. No hard freeze, ongoing warmth, and typically 300 days of sunshine during any given year. That’s a pest paradise. And unfortunately, you have to deal with the side effects.
But that’s exactly why Mosquito Squad of Pasadena exists. We’re here to help you identify the most common pests in your area, and most importantly, how to make them scarce.
Argentine Ants
You see them all the time. Scouting around in neat lines along your windowsill. Coming in through cracks and crevices you don’t even know about. Pestering you to no end. They always leave you wondering: Why do they keep coming back?
Well, it isn’t your fault. Argentine ants, one of the most persistent household pests in Pasadena, have super-colonies containing millions of diligent workers. They literally go on for miles. So, those ants you see in the kitchen are only a minuscule number compared to their massive colony. And they are nearly impossible to control without professional ant control treatment.
Black Widow Spiders
Black widows find dark corners in garages, outdoor storage, and undisturbed places to spin their webs. While they typically don’t bite unprovoked, it’s still unsettling to have them around when one bite sends you to the hospital. It’s not a risk worth taking. So, staying on top of spider control is important for everyone’s comfort in your household.
Aedes Mosquitoes
Common breeds of mosquitoes only bite at dusk and dawn, but there’s another breed of mosquito that’ll have you taking mosquito control to the next level.
The Aedes mosquito, an aggressive day-biter, is well-established in Pasadena. Because of their tendencies, it feels like you never get a break from them. They breed in very small amounts of standing water, so it doesn’t take much for them to multiply. And factoring in Pasadena’s ongoing warm weather, eggs can turn into adult mosquitoes within days. Meaning only one thing: you’ll be swatting and itching all day long.
Roof Rats
If you thought rats only scurried on the ground, you’re wrong. You’d better look up, because roof rats build their nests in trees.
In Pasadena, citrus trees, dense vegetation, and older structures provide scenery that not many places in the U.S. provide. It’s beautiful. But, roof rats take in more than just the scenery.
Your juicy, citrus fruit draws them in, and they depend on it as their main source of energy. They’ll stop at nothing to build their nests and multiply their young. And once they take over a tree or two, you’ll need professional rodent control to kick them out.
No-see-ums
No-see-ums (also known as biting midges) have their name for a reason. You can barely see them, but when they bite you… You know.
They are tiny, barely visible flies that love warm, damp areas. While similar to mosquitoes, they differ in small ways. Their larvae need moist soil, mud, and decaying organic matter to grow. So, overwatered lawns, mulch, and dense vegetation give them everything they need to thrive. And only the females bite, leaving a burning sensation and a 1-to-2 inch raised welt.
Eliminating standing water, removing debris, and avoiding over-watering will help decrease their populations. But if you combine this with professional no-see-um control, you’ll get the best results.
Ticks
Ticks are a seasonal worry among Pasadena residents. They are especially dense in the foothills and along hiking trails where many people enjoy the outdoors. However, properties all over Pasadena are also at risk and shouldn’t skip over tick control this season. Meaning, even if you don’t live in the foothills, any dense vegetation you may have attracts ticks to your property.
Also, ticks carry a swath of dangerous diseases, including Lyme disease and Rocky Mountain spotted fever. Both of these illnesses can land you in the hospital and leave you with life-changing consequences.
Mosquito Squad Can Tackle Multiple Pests at Once
You can’t have pests taking over your property (and schedule) this season. That’s why, with Mosquito Squad of Pasadena, you can repel multiple pests at once. We tackle your property with Yard Defender, a comprehensive pest control approach that reduces pest populations across the board.
You can also use Home Shield when pests decide to overstay their welcome inside your home. This service provides pest protection around the perimeter of your house without the use of indoor sprays or foggers.
Combine the two services before peak pest season hits, and you’re in for a peaceful spring and summer in Pasadena.
Wondering which pests are on your Pasadena property? Call Mosquito Squad of Pasadena at (213) 238-5564 or contact us online for a free quote.
