JANESVILLE, Wis. -- Authorities are making a Janesville man remove animals of all kinds from his home after officers said that they found more than 300 in his basement.

They said that a strange odor coming from Mark Gann's home prompted a neighbor to call Janesville police. Officers said that they found shelves stacked with cages housing birds, rodents and a few reptiles, WISC-TV reported

Investigators said that Gann was selling the animals to area pet stores.

Janesville police Lt. Tom Wolfram said that the basement was an upsetting sight.

"The whole operation was that it was pretty much an animal mill," he said. "It was sad to see a number of cages small in a dark basement crowded, raising animals for a local pet shop. People just don't realize where some of those pets come from."

Police said that they cited Gann for keeping unlicensed dogs and two illegal snakes. The property owner also ordered Gann to remove all the animals except for the dogs or face eviction, WISC-TV reported.

Animals probably won't be confiscated because there is a city ordinance that limits the number of dogs or cats in homes, but not other animals, WISC-TV reported.

Officials determined that Gann was running an unlicensed business and ordered him to stop within 30 days.