The article doesn’t mention the revolutionary discovery that was prerequisite to this study: they were able to determine which mice were male and which were female, just by looking at them.
Are you sure they didn’t ask the mice what they identified as?
But it’s now known that the variability among male animals, on a molecular and behavioral level, is usually greater than among females, so there is no reason to suppose that females would complicate the experiments any more than males.
For me, this translates to male and female mice share some of the same reactions to stress but that males have more reactions. But maybe I missed something, since I scanned over the bio-lingo that befogged my brain.
Some research mice strains are the same price, male or female, but males are generally cheaper. I wonder how much it cost them to figure all that out?