They say the rats have been getting into the lofts of their homes creating havoc by chewing through cables and leaving droppings.
One woman in Wordsworth Place said that many neighbours had been affected.
“We’ve been here 14 years and we never had any problems before the building work started,” she said.
“A neighbour had 10 rats in her garden recently.”
She said she and other neighbouring properties had had to ‘rat proof’ their lofts by putting up wire mesh and laying down poison.
She added: “The noise they make is horrendous. They scratch and scratch and wake us up about three o’clock in the morning.”
She said the problem was so bad they would move away from the area if they could afford it.
Cliff Santini and his wife Laura run Holbrook Animal Rescue Centre which is close to the construction site where 2,750 homes will eventually be built.
“We are over run with rats,” he said. “They are in the loft cavities and the barns are full of them.
“Our immediate neighbours are also infested.”
A Horsham District Council spokesperson said: “The legal responsibility to control rats rests with the owner or occupier of the land affected.
“Our environmental health records show that there has been no increase in the number of complaints regarding rat infestations in the surrounding neighbourhoods of Wordsworth Place and the construction site on the land north of Horsham development.
“Rats tend to settle in places where they can find shelter, food and water.
“Our environmental health officers always ask residents to check their gardens and refrain from feeding birds and animals until an infestation problem is solved.”