MICE and rat infestations in Hunter homes and businesses have hit earlier and harder than usual this year, pest controllers have said.
A summer full of rains combined with the recent drop in temperatures have sent high numbers of rodents inside.
Mice and rats breed year-round and heavy rains might displace them, but it also means there is lots of feed around.
Pest controllers have reported being flat out responding to calls to bait mice and rats.
Thornton-based controller Greg Hall said he had more call-outs than usual.
"Rodents are really starting to move into business and houses," he said. "I would think it's worse than normal for this time of year."
One of his suppliers was going through pallets of bait, Mr Hall said.
"Normally June and July when it's really cold they get quite active," he said.
"The [rodents] come inside looking for protection from the elements."
Hunter Reptile and Vermin Control's Peter Bryant said he recently returned from the Barrington Tops area where farmers were asking for rodent baits on properties.
He said at one of his urban clients, a Bennetts Green factory, the rat numbers were so large he was shooting rats almost weekly to help control numbers.
Mr Bryant is specially licensed to shoot rats with an air rifle and also uses baits.
"When the food chain is right their numbers just explode," he said.
"Just any food, fruit, even cardboard lying around they will eat."
Department of Primary Industries Paterson agronomist Neil Griffiths said a mice plague in NSW last year around crop farms in the Riverina area contributed to increases on Hunter farms, but the problem had eased in 2012.
"In urban areas mice problems are more likely because of underlying populations in those areas and often they become more of a problem this time of year."
Seal doors and other entry points
Do not leave pet food and water outside
Trim hedges and trees near houses and roofs
Practise good household hygiene