Section [Code of Federal Regulations] [Title 9, Volume 1] [Revised as of January 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 9CFR3.33] [Page 64] TITLE 9--ANIMALS AND ANIMAL PRODUCTS CHAPTER I--ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PART 3_STANDARDS--Table of Contents Subpart B_Specifications for the Humane Handling, Care, Treatment, and Transportation of Guinea Pigs and Hamsters Sec. 3.33 Classification and separation. Animals housed in the same primary enclosure shall be maintained in compatible groups, with the following additional restrictions: (a) Except where harem breeding is practiced, preweanling guinea pigs shall not be housed in the same primary enclosure with adults other than their parents. (b) Guinea pigs shall not be housed in the same primary enclosure with hamsters, nor shall guinea pigs or hamsters be housed in the same primary enclosure with any other species of animals. (c) Guinea pigs or hamsters under quarantine or treatment for a communicable disease shall be separated from other guinea pigs or hamsters and other susceptible species of animals in such a manner as to minimize dissemination of such disease.