Housing New Zealand is investigating the case of a nine-year-old boy in the Auckland suburb of Glenn Innes who woke up crying with two bite holes in his ear.

His mother said rats often scamper across furniture, chew through linen and scrabble under the floorboards.

Housing New Zealand said the agency has sent pest exterminators in to deal with the problem and has blocked up holes.

But they said due to the proximity of a creek and reserve, removing the rats in several state homes is proving a particular challenge.