As we’ve covered here recently, Los Angeles has plenty of challenges on its plate to deal with right now. Between an exploding homelessness crisis and a cost of living index that’s driving the middle class away in droves, their problems are quickly outpacing the resources available to deal with them. But now we can add another to-do item to the list. It seems that the city’s rat population is through the roof, largely driven by the mountains of filth accumulating in the streets. (CBS Los Angeles)

Pest control and public health experts are calling on California Gov. Gavin Newsom to declare a public health emergency over what they say is a sharp rise in the state’s rodent population.

“California is being overrun by rodents – and without immediate emergency action by state and local government, we face significant economic costs and risk a public health crisis,” said Carl DeMaio, chairman of Reform California, at a news conference Tuesday at City Hall in downtown Los Angeles.

DeMaio highlighted the findings of the group’s new report which cited an increase in the state’s homeless population, along with the elimination of the most effective pest control tools, as “significant” factors on the ongoing crisis.

The problem is actually statewide, primarily focused on the larger cities, but Los Angeles seems to be the tip of the spear on this issue. Some of their own elected officials are referring to LA as the “City of Rats” in a play on the traditional “City of Angels” moniker. Operators of pest control companies interviewed by CBS uniformly reported incidents of rat control calls being up by as much as 60% over the same time last year. None reported a decrease in calls.

So what’s causing all of this? It’s apparently a combination of factors. The homelessness crisis has led to far too many people defecating in public and the dumping of massive amounts of waste on the streets, sidewalks and any empty lots that are available. That creates a fertile breeding ground for rats and other unwanted pests.

But the state legislature has also been contributing to the crisis. They recently passed AB1788, a measure designed to ban certain “second generation” category anticoagulant rodenticides around the state. Proponents said the treatments were killing off other wildlife like coyotes. But pest control professionals claim the remaining tools of their trade aren’t effective enough to keep up with the rodent population.

Somebody is going to have to make some hard choices in terms of how badly they want to save the suburban coyotes and balance that against a million rats. (In all likelihood, there’s probably more like tens of millions. One breeding pair of rats can produce 15,000 descendants in a single year.) But poisoning them won’t work unless you can cut down on their food supply and habitat. And that means cleaning up the streets and finding more sanitary places for the homeless to rest.