Department of Health (DOH) Program Manager for Rodent and Vector Control Gerard Brown says he has been receiving photographs from across the District, showing rats congregating in small groups in streets and parks in broad daylight, which Brown said is extremely unusual behavior for rats.
None of the photos has so far come from the Capitol Hill area, Brown said. However, as the public health emergency drags on and restaurants remain closed to diners, rats are likely to get more and more innovative in searching for sources of food.
“Rats are smart, they’re genius –so they’ll figure it out,” he said.
While the idea of gangs of rats might seem threatening to people, they are unlikely to be a danger to humans, Brown said. Rather, the change in behavior shows that the rats are hungry enough to take risks. “The game has changed from when they could sneak around at night unseen and eat any time,” Brown said.
More Rats in Residential Areas
Brown and his Vector Control Team continue to wage war against the pests through the COVID-19 crisis. All 18 full-time pest controllers are working as essential workers and respond to calls to fight rats daily, doing proactive inspections and monitoring areas with known high levels of rat activity. When residents make complaints to 311, they are now received by the Vector Control Team in real time.
Rats are also increasingly being seen in residential areas, as they follow their noses to food. With people being at home now, they are generating more trash leading to overflowing trash cans. The pest control team has seen an increase in residential burrows and reports of rats in residential trash, some eating their way through the plastic lids.
“It’s not because people don’t care,” Brown said, “it’s because people have more trash than their cans hold.”
The biggest draw for rats is the food waste, Brown said, and one of the best ways to deter rats is to keep trash cans sealed and keep food waste out of the cans.
Brown says there are a few ways to make homes and trash less attractive to rats looking for things to eat. First, if your trash cans are full, keep food waste inside until just before collection times. Second, where possible, put food waste down the garbage disposal. Finally, make sure your home is rodent proofed. Rats only need a space between a quarter and a half inch in diameter to get into homes, Brown said. Check for daylight under doors or places where pipes and cords enter homes. Fill them with cement or steel wool.
Brown and his team will also come out to treat rat burrows on public property, such as tree boxes, and on private property by request. Residents can collect signatures of residents living on a particular block using a DOH petition, and then call DOH to arrange for the team to come out and treat burrows on neighborhood properties all at once, returning monthly to provide rodent treatment until rats are eliminated.
Expansion of Rat Sterilization Program
DOH has new tools in their arsenal to control the District rat population. Since December, they have been using the BorrowRx carbon monoxide producing machine, which allows pest controllers to inject gas into rat burrows and kill them instantly. Brown said the tool has been used throughout the District, including on known burrows in tree boxes on the 700 block of Pennsylvania Avenue SE. That product was only introduced in January, but Brown has expressed his confidence in the machine, which kills rats in their homes, making their burrows their graves.
A rat sterilization pilot project undertaken in partnership between DOH and pest control company SenesTech has been ongoing for the last year. The company has provided containers of ContraPest, a rat contraceptive, for placement throughout the city. Rats like the chemical, and drink it, chemically sterilizing themselves and helping to lower the rat population. According to SenesTech, under ideal conditions, two mating rats can produce up to 15,000 descendants in one year.
Although Brown is reluctant to deem the sterilization project a success, he said that early observations indicate that the District is seeing a reduction in rat populations. Now the program has been extended, with SenesTech offering to supply a few hundred containers of ContraPest to prepare for the reopening of the District
In Ward 6, ContraPest boxes are currently located on the 200 block of Seventh Street SE, across from Eastern Market and on the 1300 block of H Street NE and Wylie Court. Boxes are indicated by signs and will be listed on the DOH website.
Brown encourages the public to call and report rat sightings, especially if they see rats behaving in ways they have not seen before, such as gathering in groups, or congregating in the daytime. “If that happens, we want to increase our inspections and treatment in those areas,” Brown said. “But the only way we’re going to find those areas is if residents are telling us.”
Ways to Fight Rats:
- Rodent-proof your home by sealing openings larger than ¼ inch in diameter.
- Close trash cans tightly.
- Avoid keeping food waste in trash cans.
- Use garbage disposal as much as possible.
- If the trash can is full, keep trash in your house until just before collection.
- Contact DC 311 or the DOH Vector Control Team with rat sightings or other concerns.
- Request rat abatement in public spaces at dc.gov/citizen/home
Call 202-535-1954 for rodent control information, outreach, educational materials, and enforcement. Find the neighborhood petition for rodent treatment at doh.dc.gov/sites/default/files/dc/sites/doh/publication/attachments/Rodent%20Petition.pdf