Millions of American homeowners face foreclosure, but at least one sort of housing crisis has been remedied: No longer will research rats suffer the indignities of crowded cages.

That is to say that the federal government has ordered labs to provide precisely measured living quarters for all rodents used in federally funded research. Thus, a female rat and her offspring must be housed (for their short, genetically altered lives) in lodgings that feature no less than 124 square inches of floor space and 7 inches of head room. By comparison, a mama mouse and her litter merit a mere 51-inch area. (Space taken up by food bowls, water containers, litter boxes, and toys doesn’t count.)

The new requirements appear in the latest edition of the Guide for the Care and Use of Laboratory Animals (page 57), published by the National Research Council. No such requirements have appeared in previous editions.

Researchers are alarmed, to say the least. According to the National Association for Biomedical Research, the new standards will increase lab costs by hundreds of millions of dollars—chunks of it from taxpayers—thereby detracting from research projects. Scientists also say there’s no evidence that luxury cage space will have any positive effect on Rattus norvegicus.

Alas, the opposition doesn’t faze the folks at the National Research Council, who warn that “departures from the Guide for reasons of convenience, cost, or other non-animal welfare considerations are not acceptable.”