Can Rodents Become Resistant to Rodenticide?

Controlling rats is about much more than putting poison down. Especially now that it appears in recent years, rats have developed a resistance to rodenticides. So why have rats became virtually immune to some poisons and what does that mean for rat control?

Can rats really become immune to poison?

You’ve probably read the horror headlines about the giant super rats who are immune to poison. But this is not a new thing. A couple of decades ago, researchers noticed that rats were developing resistance to rodenticides and they say that this is only going to get more common. But what’s the reason for the existence of these so-called ‘super rats’?

The rise of the ‘super rats’

‘Super rats’ aren’t just big or aggressive rats. Researchers used the term back in 2012, when a report was published, stating that as much as 70% of the rat population in England are immune to commonly used rodenticides.

Why is this happening? Well apparently, it’s down to their genes. Researchers have found that there’s a specific genetic mutation that gives them immunity.

The way rodenticides work is by depleting the amount of vitamin K in rats’ bodies. Vitamin K usually helps the blood clot in the event of bleeding. Without enough vitamin K, the anticoagulant action of the rodenticide would cause them to bleed to death. However, this didn’t have any effect on the rats with a mutation in the gene that controls vitamin K levels in their bodies.

Rats with this genetic advantage live longer and so they pass on the mutation to their offspring who also become immune to rodenticides.

Will rat poison affect ‘super rats’ at all?

Some rats don’t fall into the completely immune or not immune camps. Some are ‘semi-immune.’ While some will survive ingesting poison, some will ingest it and still die, they’ll just die more slowly or their life span will be cut short.

Resistance to rodenticide: which poisons are rats becoming immune to?

Rats are developing immunity to anticoagulants such as warfarin and they are also developing immunity to other poisons. According to researchers who were trying to figure this out, brown rats changed their behaviour so they didn’t consume a dose of the poison that would kill them. Rats by nature are very cautious, so if you put out a new poison or bait a trap, don’t expect them to go straight for it, if at all.

Why aren’t rats eating the bait I’ve put down?

It could be that they’ve found something better to feast on, or like we’ve just said, they are probably being cautious. If you want baits that work, you have to choose something that’s geared towards the particular scents that rats like.

Can’t get rid of a rat problem?

Contego’s expert technicians have access to the most effective, professional strength products on the market as well as other tricks up their sleeves, such as SMART pest control.

If you have a rat problem in your home or business, don’t waste time letting them breed and spread diseases while you try to figure out why your rat control tactics aren’t working.

Claim your home or premises back and get peace of mind that your rat problem is under control once and for all.