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Newton, Massachusetts Joins Cities Across the U.S. Using ContraPest® to Control Soaring Rat Populations
ContraPest® is the First and Only EPA Approved Birth Control for Rats.
Without fertility control, two base rats, a male and a female, can produce generations of rats, resulting in more than 15 thousand rats in just one year. ContraPest® is an Effective and Environmentally Responsible, 21st Century Solution to an Age-Old Problem.

PHOENIX, Oct. 26, 2021 /PRNewswire/ -- Just one year since SenesTech  (NASDAQ: SNES) (, the rodent fertility control experts, transitioned from a science-based research company to a commercial one, municipalities around the United States are using its rat contraceptive, ContraPest®  as they work to combat soaring rat populations. Newton, Massachusetts now joins other cities like Hartford, San Francisco, and Washington DC successfully incorporating ContraPest® into their pest management programs. It is the one and only EPA approved birth control for rats and is a non-toxic, non-lethal, long-term solution to controlling rat populations made even worse in cities due to the pandemic. ContraPest® has demonstrated unprecedented success in reducing rat populations, often by more than 94 percent, in an environmentally responsible, sustainable manner.

"Newton is the latest forward-thinking city to deploy ContraPest® and we expect more municipalities to follow since the results have been so positive. Cities especially have always been plagued with rat problems and they have gotten much worse with the pandemic. At the same time, local governments are also concerned about the environment and want a solution that does not harm other animals, pets or people," said Ken Siegel the CEO of SenesTech, the developer of ContraPest®. "Our birth control for rats dramatically amplifies the success of integrated pest management programs and provides a long-term solution to rat control as opposed to a quick fix that doesn't last."

Results include:

  • In Washington DC, at one site, there was a 94 percent reduction in rat activity and a 98 percent decline in juvenile rats. At the second site, there was a 99 percent reduction in rat activity and 100 percent decline in juvenile rats during the same period.
  • The city of San Francisco deployed ContraPest® in parks and saw a 65 percent reduction in rat burrows.
  • The City of Hartford began seeing positive results within two months of deployment.

Birth control is essential to controlling rat populations since two base rats, a male and female, can produce generations of rats, resulting in more than 15-thousand rats in just one year. Rats reproduce faster than poisons, traps or any other lethal means that can eliminate them. Without birth control, their population rebounds to its original level within a few months of using traditional rat control methods. 

ContraPest® is a liquid formulation that is high in fat, sweet tasting and very attractive to rats, which need to consume approximately 10 percent of their body weight in water each day. Deployed in traditional bait boxes, ContraPest® targets the reproductive capabilities of both sexes in rat populations, inducing egg loss in female rats and impairing sperm development in males. 

"We call ContraPest® a milkshake for rats since they love the taste so much. It is usually deployed monthly and rats need to consume it on a regular basis for continued effectiveness," said Brandy Pyzyna, SenesTech's Vice President of Research & Regulatory Affairs and one of the scientists who helped develop it. "As long as ContraPest is being used the rat population will not rebound. Our researchers are working on developing birth control for other pests as well. We hope to introduce those products in the future as we continue our mission to transform pest control in a safe, sustainable, effective way."

ContraPest® is available for use in all 50 states and the District of Columbia. Sales revenues for ContraPest® in 2021 are up over 100 percent from the previous year. The state of California accounted for nearly a third of SenesTech's revenue so far this year. California enacted legislation in January 2021 prohibiting the use of the four major second generation anticoagulant rodenticides under many circumstances. Other states and municipalities are considering similar legislation further accelerating the market for non-lethal, effective pest control alternatives. More information about ContraPest® is available via the SenesTech website (

About SenesTech
SenesTech is "The Pest Control Difference" for the 21st century. We are rodent fertility control specialists fueled by our passion to create a healthy environment by virtually eliminating rodent pest populations in a safe way that does not harm other wildlife.  We invented ContraPest®, the world's first and only U.S. EPA registered rodent contraceptive.  By controlling their fertility, ContraPest® provides a new, non-lethal and proven solution to reducing rat populations often by more than 94 percent.

ContraPest® fits seamlessly into all integrated pest management programs and greatly improves their effectiveness. It is transforming the pest control industry in an environmentally responsible way. We strive for clean cities, efficient businesses and happy households—all through non-lethal, proactive pest control. At SenesTech, we don't just eliminate rats. We make a better world. For more information visit and

Safe Harbor Statement This release contains "forward-looking statements" made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may describe future expectations, plans, results, or strategies and are generally preceded by words such as "believe," "may," "future," "plan," "will," "should," "expect," "anticipate," "eventually" or "projected." You are cautioned that such statements are subject to risks and uncertainties that could cause future or actual results to differ materially due to a number of factors and other risks identified in our filings with the Securities and Exchange Commission. Forward looking statements include, but are not limited to, our belief that ContraPest® will establish a new paradigm in rodent control and that ContraPest® will increase the effectiveness of rodent control in all IPM program, our growth potential, market opportunities and the continued use of ContraPest® by customers.  All forward-looking statements contained in this press release speak only as of the date on which they were made and are based on management's assumptions and estimates as of such date. We do not undertake any obligation to publicly update any forward-looking statements, whether as a result of the receipt of new information, the occurrence of future events or otherwise.


SOURCE SenesTech, Inc.

For further information: Anne Kavanagh (847) 682-3422