Laurie McCannon, director of the Northeast Animal Shelter in Salem, Mass., with a dog named Trina. Three-quarters of the dogs adopted from the shelter in 2013 were from out of state. Shannon Mullen for NPR hide caption

itoggle caption Shannon Mullen for NPR

A puppy waits at an adoption event in Miami last year. The city is now considering a ban on the sale of puppies in retail pet stores. Cities and towns in several states have passed similar bans, aimed at cracking down on substandard, large-scale puppy breeders. Wilfredo Lee/AP hide caption

itoggle caption Wilfredo Lee/AP

A curious cuttlefish stares back at the camera from inside The Smithsonian's National Zoo Invertebrate Exhibit. The exhibit, home to dozens of small aquatic and terrestrial species without backbones, closed on Sunday. Meghan Murphy/Smithsonian's National Zoo hide caption

itoggle caption Meghan Murphy/Smithsonian's National Zoo