It's a safe bet "woolly mice" weren't on anyone's bingo cards today, but sometimes something comes up in the daily news that's just so odd that, as a biologist, I have to remark on it. In today's episode of "science types messing around with things we don't understand," Colossal Biosciences, the Texas company that is trying to resurrect, among other extinct critters, the woolly mammoth, has now produced... woolly mice.

Yes, really.

Scientists have genetically engineered mice with some key characteristics of an extinct animal that was far larger — the woolly mammoth. 

This "woolly mouse" marks an important step toward achieving the researchers' ultimate goal — bringing a woolly mammoth-like creature back from extinction, they say.

"For us, it's an incredibly big deal," says Beth Shapiro, chief science officer at Colossal Biosciences, a Dallas company trying to resurrect the woolly mammoth and other extinct species.

Note that Colossal Biosciences is a privately funded venture, as far as I'm able to ascertain, with no requirement that they remain anony-mouse.

What's not at all clear is whether these mice are really "woolly." The term is generally used to denote an animal who, like the extinct woolly mammoth and woolly rhinoceros, had a distinctive winter coat consisting of a thick, woolly underlayer covered with long, stiff guard hairs. There are animals with similar setups today - bison, for example. In summer, they tend to lose the woolly coat and end up looking rather diminished until fall, when the woolly layer grows back.

The company announced the creation of the woolly mice Tuesday in a news release and posted a scientific paper online detailing the achievement. Scientists implanted genetically modified embryos in female lab mice that gave birth to the first of the woolly pups in October. 

"This is really validation that what we have in mind for our longer-term de-extinction project is really going to work," Shapiro told NPR in an interview. The company says reviving extinct species like the mammoth, the dodo and others could help repair ecosystems. Critics, however, question whether de-extinction would be safe for the animals or environment.

Forget safe - I'm skeptical about their claims of being al-mouse-t there in their de-extinction effort. If you look at the mice in question, they are clearly long-haired, but Colossal may be squeaking by on the "woolly" claim. Here, have a look:

They've spliced woolly mammoth genes into mice.

There are now... WOOLLY MICE.

If you don’t wanna talk about this, we have nothing to discuss. pic.twitter.com/xRmumlJfqw

— Isley (@IsleyResistance) March 4, 2025

Note that this note is incorrect in one sense: Colossal did not splice mammoth genes into mice. What these mouse-terminds did was switch on a gene that is common to mice and mammoths, a gene that controls hair growth. So, long-haired mice. Not necessarily woolly mice. They are cute, though.

See Related: Report: 35,000-Year-Old Frozen Saber-Tooth Kitten Found in Siberia

Texas Company Claims They Will 'De-Extinct' Four Species by 2028. Spoiler: They Won't.

Now, there is an opportunity here, one that doesn't involve the creation of, say, a saber-toothed squirrel or anything like that. Think of the potential of the pet market! These adorable little fuzzballs, assuming they breed true, would sell like hotcakes in the pet stores. Colossal may recoup a lot of research money by selling adorable fuzzy mice. It's an option they should take seriously because they aren't going to bring back woolly mammoths any time soon.

This seems appropriate.