City inspectors were sent to the 6,100-square-foot Global Captive Breeders facility in Lake Elsinore last week because of cruelty complaints filed by an animal rights group.
City Manager Grant Yates says code enforcement officers found decaying animal carcasses and animals near death in their enclosures.
The Riverside Press-Enterprise (http://bit.ly/TtnSbl) says more than 18,400 rodents and about 600 reptiles, mostly snakes, had been counted by Monday.
The rodents were being raised to feed the reptiles.
The Global Captive Breeders facility telephone is disconnected.
A voicemail message left Tuesday at company headquarters in Rancho Santa Margarita wasn't returned.
Information from: The Press-Enterprise, http://www.pe.com