Neighbors along Union Street in Westfield say they are under attack. Their homes are being invaded by dozens of rats.

"I just want it out," said Tammy Kopy, who was searching frantically for a rodent just moments before we showed up.

"I was on the phone, and my mother in law asked, 'what's the matter,' and I said 'there is a rat in front of my bathroom door.' I got up and did not know where he went," Kopy said.

And she is only one of several residents facing the same problem of close to 200 rats flooding the streets and nearby homes.

"They are huge, greasy, disgusting," said Allison Hall, a neighbor of Kopy's.

Those are only a few of the words these residents are using to describe the rats. They are moving into homes after construction crews disturbed their habitat in the sewers as part of the Great River Bridge project. Hall said she has seen more than two dozen herself.

"They hissed at my sister. They hissed at [my neighbor's] mom. It's sad that we can't even go outside without having to worry about rats," she said.

Now, the exterminators are playing catch-up, lining the sewers with poisonous bait traps in an effort to prevent more rats from making an unwelcome appearance.

"If they're taking more bait, we'll just supplement it with more bait until it's stopped. That's the only way we'll know we've controlled the population," said Don Kozaczka from Westfield Exterminators.

But that could take as long as two weeks, for something even the city's public health director, Dan Reardon said was a huge oversight. Preventative exterminations should have been part of the construction contract. It was not.

"I was just talking with Mayor Boulanger and the city engineer, and we've agreed that for all future contracts in the urban core, that this component will be put into all contracts of major excavations," said Reardon.

Reardon signed a new contract Friday for the exterminating work. The cost will be covered by the city at a price of $2,365.

Kozaczka said that, besides any underlying health risks, rats are usually not aggressive unless they are cornered. He said a good tip to keep rats away from you, is to keep food and garbage away from them.