Rats

For centuries, Castle Island stood as a bulwark against foreign invaders. But in 2012, the popular South Boston park battled domestic intruders: rats.

“They’re overwhelming; it’s infested all over the island,” said Bill Spain, president of the Castle Island Association, a nonprofit historical preservation group. “It’s really bad at night. Someone is going to get attacked.”

Over in Downtown Crossing, officials recently passed out violation notices to property owners in an effort to crack down on infestation from rats, pigeons, and cockroaches.

While inspectors said they pay attention to Downtown Crossing throughout the year, they launched the inaugural seasonal blitz because they received complaints and have seen problems there in the past, and because of high traffic from shoppers and tourists.

Pictured: Rats spotted by Queensberry Street near Fenway.