Once near domination, wild rats have now met their match.

rat traps

A mix of people stood at a bus stop in the Belmont neighborhood of the Bronx. Some were headed home after a long day of work. Others were heading out to dinner or drinks. Nobody could have predicted what was about to happen next. Straight out of a horror movie, it seemed the sidewalk opened and swallowed one of those waiting for the bus. His name was Leonard Shoulders. He’d fallen twelve to fifteen feet into an underground vault filled with rats. It took thirty minutes for firefighters to get him out, and he kept his mouth shut the whole time. Why? He was worried a rat would get into his mouth. The rats are winning!

The myths we have been telling ourselves.

Myth Number One: We can kill our way to success. 

The seemingly singular approach to rat control has long been a game of whack a mole. 

See a rat. 

Put down poisons and traps. 

Rats disappear. 

But they eventually come back. 

All you need to know about rat control is this: Rats can make babies faster than we can kill them. 

All the rat poison, rat traps, and ratting dogs we’ve been using have done nothing to change that. So the rats are winning, and our approach isn’t. 

Myth Number Two: Rats are only a problem in big cities

Rats are a huge problem in the agricultural/farming world and even in many small towns. 

Myth Number Three: Rat poison is safe. 

Rat poison is dangerous to children and pets. It’s also non-biodegradable, which means it will stay in your soil for a very long time.

Wild Rats vs. Domesticated Rats

Don’t get me wrong. I’m an animal lover, but there’s a significant difference between domesticated rats and wild ones. Domestic rats are cute and cuddly.

There are even rats trained to help humans in earthquake situations and to detect land mines.

Wild rats, though, are a different story. They are unhealthy and even dangerous to humans. 

Meet the competition

Rats are tough competition. They are SuperRodents!


Take a look at some of their daily feats

  • They can scale the sides of buildings like Superman
  • They can wiggle through pipes like Elastigirl
  • They can hold their breath for minutes at a time like a Navy Seal

Perhaps most epically, however, is just how much sex rats have! And along with tons of sex comes– you guessed it, TONS of babies. 

A day in the life of a wild rat

Let me help you imagine a day in the life of the majestic wild rat. After a long sleep in hiding, the rat awakens in the evening, ready to start his day. He notices a discarded box and starts gnawing. He knows it may take some time to find tastier nibbles. 

When the coast is clear, he sprints over to a mouthwatering sight – a garbage bag pile in front of a restaurant. As he runs over, he can’t help but create a small path of stool from his appetizer. 

He eats until he can’t eat more. He is enjoying the moment but suddenly hears a noise that sounds like danger. He looks around and sees safety! He climbs into a drainpipe and wiggles through until he reaches a pool of water. 

He holds his breath for what seems like hours (but is, in fact, only 4 minutes) and risks running back through the pipe to the street. 

Back on the street, he remembers his plan to rendevous with his lady rat friend. To get to their date spot, he runs to an old brick building on the corner and uses his powerful hind feet and sharp claws to climb his way to the roof. They flirt for a bit, each showing off for the other. But, then, one thing leads to another, and…

Birth control for rats? 

If someone wants to get rid of rats, what can they do today that is different?

Contrapest is birth control for rats. You read that right! 

Contrapest was born (excuse the irony) from the all too true idea that we will never kill our way to no rats. The fact is, it is not mathematically possible. Why?

  • Rats can go into heat within forty-eight hours of being born. These are the babies going into heat, not the mothers!
  • Female rats can start birthing within two months of their own birth.
  • Mature female rats go into heat every four to five DAYS.
  • A rat can birth 5-12 baby rats per litter.

You do the math! Traditional rat control simply does not work.

How is Contrapest administered?

Contrapest is a milky substance that rats can freely feed on.

contrapest for rats

Case Study: Washington DC

Contrapest was used in a study in Washington DC to rid an area of rats. Contrapest bait stations were placed in multiple controlled locations in Washington DC. The existing rat-control methods that were already in place (not succeeding) remained during the experiment. These methods included:

  • Rat poisons. 
  • Clearing the areas of garbage. 
  • Making it hard to enter buildings and spaces with garbage. 
  • Physical rat traps. 
  • Environmental factors like birds that eat rats, etc. 

Video cameras were placed at each bait station to track the number of rats seen daily. 

As a result of the study, rat sightings greatly diminished. Here are some of the hard numbers: 

  • The total number of rat sightings declined 96% after Contrapest was deployed. 
  • The decline of juvenile rats was almost 100% which was a great sign that new baby rats weren’t being born. 
“Following the completion of a four-month study of the effectiveness of Contrapest, there is no longer any doubt that Contrapest is an effective treatment for rat control.” –Ian Gilson, ZACKS SMALL CAPITAL RESEARCH

Contrapest has another successful case study they did at a poultry farm


Contrapest doesn’t make rats permanently impotent. The studies show that a few weeks after consuming Contrapest, rats can once again have babies.

In order to increase effectiveness and significantly reduce the population of wild rats, they must keep eating Contrapest.

What are the benefits of Sensetech’s Contrapest?

  • Poison-free
  • More humane
  • More effective

Can Contrapest alone get rid of a rat population? Probably not, but if you include Contrapest with traditional methods, you have a much better chance of success. 

Thank you to Nicole Williams, Chief Strategy Officer at Senestech, for helping create this article.

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of SparkyGo.