There are plenty of factors that can impact your car insurance premiums.
A recent endorsement on your driving licence, a rise in motor theft in your postcode, or a change to a more powerful vehicle can all send your policy prices spiralling.
But one contributing factor to premium increases you might not expect is... rats.
However, rodent-related motor claims have jumped in the last year - and are predicted to soar this winter with predictions of a major rat infestation over the coming months.
Insurer Aviva said it dealt with 28 per cent more motor claims involving rodent damage in 2024 than the year previous - and it the colder months of December and January when incidents spike.
The average cost of fixing damage from rats gnawing through wiring and other components also increased by 11 per cent, which is pushing average premiums higher as a result.
Motorists are being told to remain extra vigilant over the coming weeks, with experts predicting a surge in rats linked to an unusually high acorn season.
The average claim for rodent-related vehicle damage last year was £2,494 compared to £2,253 in 2023.
In one case, a customer's car suffered an estimated £24,000 of damage thanks to rats, which made the repair uneconomical and resulted in the vehicle being written off.
And Aviva's rodent report says rats can cause severe damage that have a major impact on safety and could put drivers, passengers and other road users at increased risk.
The most common finding is rodent nets within engine compartments and behind passenger airbags.
Given the flammable materials typically making up a rat nest and proximity to a hot engine and fluids, there is a major risk of fire.
Another cause of concern is rodent attacks on wiring and cabling, with rats chewing through looms that can impact both internal and external electrics, sensors, batteries, suspension system and gear mechanisms.
And they've also been found to have gnawed through seats, seatbelts, footwell carpets and other parts of a car's interior that are expensive to replace.
Fuel and water leaks caused by rodents biting into fuel tanks and piping systems have also been reported.
This increase in volume and cost of claims related to rat damage will be having an impact on average premiums, if not one that triggers a huge increase in pricing.
James Driscoll, motor claims manager at Aviva, warns we are now coming into the season when rats are most likely to cause vehicle damage.
'Many people are aware of the damage that rodents can cause to properties, but may not realise they also like to explore our cars,' he said.
'In the winter months, mice and rats look for warmer places to nest and they can squeeze into the tiniest of gaps, including the grilles, vents or open windows of vehicles.
'And once inside a car, rodents can cause significant damage.'
James says the issue tends to be more prevalent in larger cities, where higher population density, extensive drainage networks, and ageing infrastructure create ideal conditions for vermin to thrive.
'It's worth being extra-vigilant, especially during the winter months. If you notice any signs of gnawing or suspect rodent damage in your car, contact your insurer straight away who will be able to assist, reducing the chances of potentially costly repairs and anymore rat-astrophies.
'Coverage will vary from insurer to insurer, so it's worth reviewing your policy details to check if you're covered.'
Experts are warning that 2025 has been a bumper year for acorns, fruit and nuts - and this is likely to trigger a surge in pests, especially rat activity.
It comes as pest controllers have recently reported catching rodents more than 20 inches long amid a 'horrendous infestation'.
A warm, dry spring followed by an early autumn means 2025 is shaping up to be a 'mast year', environmental consultants revealed.
These happen every five to 10 years and occur when certain trees and shrubs produce a synchronised bumper crop of seeds, fruits and nuts.
An abundance of nuts and berries – especially on woodland walks – is a telltale sign.
However, it can also lead to increased activity from the likes of rats, mice, acorn weevils and moths.
Have you had a car damaged by rodents? Get in touch: [email protected]