Rat populations in cities like Berkeley swell in the summer months. Photos: Reg McKenna

By Robert Mills

Rats and other rodents are out and about. The cunning, nocturnal critters seem to grow in numbers during the hot summer nights, and Berkeley residents can do their part to cut down on their nighttime scavenging.

“We need to remind the community that there are things they can do to eliminate outside food, water and places where rodents can live,” said Manuel Ramirez, general manager of the city’s Environmental Health Department. “We respond everyday to overgrowth of vegetation, and we get a lot of people leaving out pet food and bird seed.

“Those are perfect sources of food for rodents and other wildlife.”

One Berkeleyside reader reports that when she recently called in pest control they said there was currently a rat infestation  in Berkeley.

Ramirez said swells in rodent populations during the summer are directly related to increased human activity. When the days heat up and get longer, more people get careless about litter and leftovers, he said. Scraps from barbeques and standing water from kiddy pools make the perfect food and water sources for nesting rats.

“People need to be cognizant that we live in a very populated area,” Ramirez said. “Rodents are part of the ecosystem. We provide food for them. Most people don’t think about that. The easiest way to control them is to eliminate those food sources.”

A clean yard will cut down on rodent activity. Ramirez advised to clean up extra brush, dog waste and fallen fruits from fruit trees.

“If the rodent population gets out of hand, people want to apply pesticides,” he said. “Pesticides have risks associated with them. The best thing to do is eliminate the contributing factors.”

For more information about protecting your home from rodents, visit the Environmental Health website.

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  1.  Maybe you saw a vole, aka field mice. They’re bigger than a mouse and smaller than a rat and really cute and really destructive in the garden. They have longish hair and short tails. They love to eat the bark off young fruit trees. Northern California, including Berkeley, has experienced a population explosion of voles this year.

    My first vole sighting was last winter. I watched a rolypoly rodent sitting on its haunches eating a dandelion leaf. It rolled backward in ecstasy, then sauntered back to its home under the hedge.

  2. I saw the first rat of the season in my back yard yesterday morning.

    Cute little sucker! Very small for a rat. Looked more like a very large mouse than anything else.

    I don’t mind the rats so much. I’m more worried about raccoons. One of my neighbors had a pet chicken killed by raccoons, and they’ve knocked over our garbage cans a few times.

  3. Sorry, I don’t mean to conflate the issue of pigeons with rats — my point was only that the guy is dumping TONS of birdseed at several locations.  I mean, it’s a LOT of birdseed.

  4. Berkeley’s own Pigeon Man is major contributor to the problem .. as previously noted in the comments here:


    “The person who dumps that seed (almost nightly is a pigeon lover, drives a new Honda Fit, CA license 6EVK287, he’s about 6’1, maybe 60, full head of short gray hair, athletic, wears cargo pants. ..”

    I’ve personally confronted this person (same description, car and license plate) feeding the pigeons in front of Berkeley Bowl, notably in the area where the cars and sidewalk are covered in bird feces.   He’s very combative and clearly a little nuts about his pigeons.  

  5. I was just walking along College, from Ashby to Haste. Scurrying across the sidewalk I saw two different mice. Or else baby rats just starting to grow. They were big for any house mice I know but too small to count, yet, as rats.

    Both of these rodents were heading towards houses, not away! Each burrowed into cracks in cement retaining walls along front property lines. They were going somewhere there was food, I bet.

    Then, I took Haste to Telegraph and looked for signs of the rats Berkeleyside showed last year. I also looked for corn and other feed that was thrown on that lot in the past, attracting rats. I saw no rodents or feed. Progress? Well, I did not take this route to look for rodents. I just happened to remember Berkeleyside’s story about rodents and feed on that lot at Haste & Telegraph. That empty lot is so wrong.

    Real progress on that corner would be a thriving building, maybe with street level retail, upper level apartments or office space. Or at least let someone grow food on that sunny lot!!

  6. Thanks for the informative link.  It’s interesting to juxtapose the advice in that vector control resource with the trend toward home food production, including fruit trees.  In a similar vein, I see that bamboo is discouraged because it draws rats, and yet that’s very commonly used in landscaping around here.  There’s no free lunch, I guess, unless you’re a rat.

    Before replacing my foundation I used to have pretty regular rat issues.  When I spoke to vector control — great people, by the way — they let me know that rats travel along the perimeter of a wall.  So set those traps along the wall, not in the middle of an open space.  Also, you can see signs of rodent entry on cracks and gaps in structures pretty easily — their fur leaves an oily smudge.  One thing that can help seal small gaps is steel wool, as they can’t chew through that.  Finally, the most effective bait that I ever devised was to hook a bit of cotton (about as much as one side of a Q-tip) on the trap and then cover that with peanut butter.  The rat’s teeth get caught in the cotton when they eat the peanut butter and when they pull back, blammo!  Just be sure you get the (larger) rat-sized traps instead of the mouse traps or you’ll have to deal with a wounded rat, which can be… unpleasant.

  7. What’s worse than finding a dead rat in your attic? Finding half of a dead rat…because then you wonder who ate the missing half?

  8. We call the Berkeley roof rats “squirrats,” because they are rats that act like squirrels – as opposed to the “raquirrels,” squirrels that act like rats…another common sight around here.

  9. Why isn’t that they look so cute when they are in a picture and look soooo disgusting when you see it running across a room?