The number of rats and mice found indoors has increased substantially in recent months, according to the National Pest Technicians Association.

The NPTS is to meet officials from the Department of Agriculture to discuss the situation.

Chris Izart, a spokesperson for the association, said that last November the Food Safety Authority of Ireland recorded the highest number of closures since it was first established over 20 years ago.

He told RTÉ's News at One that many of these closures related to rat and mice infestations.

"We started to wonder, what's the problem? Why do we have more rodent infestations, especially indoors?"

Mr Izart said this winter's heavy rain could be one contributing factor as it would drive the rodents out of their burrows and indoors but added that new rules around pest control are "significantly adding" to the problem.

"The rules have been developed following some new directives. Many of the concerns are about risk to wildlife because of poisoning."

He explained that, previously, tamper-proof boxes containing rodenticide poison would be laid to prevent an infestation from happening.

However, according to the new rules, this can not be done until there is evidence of an infestation.

Restaurants that might have had traps in place to prevent rodents from settling in the first place must now wait until there is evidence of rodents.

"This has significant consequences - especially indoors - in the frequency and duration of the infestation."

Mr Izart added that pest controllers have noticed a 40-60% increase in rodent infestations indoors.

"This makes it challenging to rapidly respond to emergency calls. There's an increase in the time it takes to regain control after an infestation happens. This could increase public health risks because of the contamination associated with rodent urine or droppings."

The new rules were brought in as a result of European Union directives. But Mr Izart said some countries have been "very successful" at implementing the rules "in a slightly different way."

The UK has implemented "a happy medium," he said.

"They have restricted the use of rodenticide outdoors where wildlife can be present, but they have allowed it to remain indoors where there is no risk to wildlife. But at the same time, there are major risks to human health."

Mr Izart said a similar interpretation of those rules here would "really help" the situation.

"In an ideal world you would use nothing, but you cannot live with rats and mice. They are too dangerous".