Tuesday, August 18, 2009

Mole-Rat Babies

Call them ugly or cute, you must see our baby naked mole-rats. Looks aside, we are very excited to have developed husbandry protocols that helped get them through their crucial first week of life.

Eighteen months ago, the prospect of rearing mole-rat pups was a distant hope. Our colony was in serious trouble. We had lost half a dozen workers in as many months. Inexplicably, each animal’s necropsy (animal autopsy) showed unique causes of death –there was no single cause.

Making any major changes to these animals’ care is risky. As eusocial animals, mole-rats depend on scent cues to recognize members of their own colony. Any antibiotic treatment must be carefully developed to avoid killing their life-giving, symbiotic bacteria.

Two things caused me to consider trying antibiotics and husbandry changes. One was negative: the losses in the colony. Despite my fears about treatment, the risk of doing nothing was greater. The positive side was our new veterinary service, Avian and Exotic Animal Hospital . Dr’s Maas and Ferguson were committed to develop a protocol to bring the colony back into perfect health. They carefully examined the animals, testing their blood, stools, urine and nostrils for signs of infection. In due course, they developed treatment designed with mole-rats’ delicate digestive and behavioral needs in mind.

After two intense weeks of daily injections for each of our 23 colony members, bleaching their home and replacing all their contact surfaces, we saw glimmers of hope. Animals started gaining weight and the mysterious deaths ceased.

But the first pregnancy after these treatments ended badly. And over time, pups were born but the colony appeared unwilling or unable to rear them.

Interfering in the behavior of highly social animals often does more harm than good, but our colony had come to a reproductive standstill – adults were doing well, but the babies could not survive. Perhaps the colony, lacking experience with successfully rearing pups, needed some adjustments, at least to successfully bring up one litter.

Three days before her due date, the pregnant queen and two helpers were settled in chambers separated from the rest of the colony. To keep all the workers familiar with their queen, we switched one worker every morning and one each night with a new mole-rat from the colony.

When the queen gave birth, the helpers appeared calm but interested in the babies. By the next day we saw encouraging signs – a tiny white region in each pup’s middle indicated milk had made its way into their bellies.

On the tenth day (August 17), the pups were old enough to right themselves and move independently. Soon they will show interest in solid food. Next we can begin reintegrating the queen and her helpers into the colony.

The first year of a mole-rat’s life is one of challenge but with the most difficult ten days behind them, these pups are off to a good start!

Congratulations if you read this far! The first person to post a comment or question below wins a “behind the scenes” chance to help us care for the mole-rats, and if you wish, you may help choose color markings to identify the new babies.

-Sarah Moore, Life Sciences program manager


  1. I love the first picture up top of the babies. What is interesting to me is to see those 2 bulging skull plates (I'm sure they have anatomical names) that will fuse together in development. Compared to the adult NMR skeleton that is sitting on my desk, they are super pronounced.

    Congratulations, Presumptive Queen!

  2. I hope you can see the little white spot on the back of the top baby. That's actually a drop of milk - proof that s/he's getting nourishment!

  3. Congratulations Portia, you are the winner.

    Portia is a long term, big time help to the life science department. She might have already gone behind the scenes with the mole-rats, and if so is free to share the prize with our next post.


  4. Looky! People at the Science Center are doing science! It's so magical and adorable! Great work.

  5. The extra info about those pictures makes them especially fascinating! Best of luck to our new NMR friends!

  6. I love the naked mole rats!!! It that my hand in the picture holding the adult? I wish I got the behind the scenes.... darn. :(


  7. Great work finding and fixing the cause of the poputation decline! As Bill Nye the Science Guy says "They're naked! And their mole rats!"

  8. Yes, Lauren, that is your hand :) and you've been behind the scenes. Maybe Portia will let you choose the color markings for one of the babies?

  9. How absolutely wonderful and interesting. This is my first time looking at your website, and I will be back for sure.

  10. So darn ugly, and yet, I absolutely love them.

  11. omg i would love to go behind the scenes...that sounds so much fun...my family loves the science center

    GoGo (Florence)

  12. We will be offering more behind the scenes opportunities in the future, and I will be looking for non-staff member winners.

    Please keep checking back.

  13. to bad your not in new zealand! they've got to be my favourites!

  14. My son just uncovered a nest of baby moles in our yard. He thought they were bunnies and needed to be rescued. Thankfully he got me before he touched them. We can now watch them grow without interfering, and have posted a plant protector around them to prevent the lawn mower from getting to them. Science is always best viewed at it was intended to be viewed, naturally! Good luck. R from Eden Prairie MN

  15. stoll1@u.washington.eduOctober 5, 2009 at 3:20 PM

    This is a really informative posting! Colony dynamics can be difficult, and it seems the issues are only compounded with an unfamiliar, eusocial species.

    I'm a graduate student in the neurobiology program at UW, and am studying the connections between aging, neurogenesis and cancer. I've recently become interested in naked mole rats, due to their unusually long lifespan and rare occurrence of tumors (among their other endearing traits). I'd love to check out the colony!

  16. How wonderful! I am so happy things are looking up for the NMR friends! One of my favorite parts of the PSC (of which my family are members).

  17. ugly but cute mole rat babies, thank you for your post I had to write a paper on necropsy for next week and I found your blog very helpful!

  18. can a naked mole rat live with out the colony?

  19. Anonymous, naked mole-rats can survive alone but they do not live as well or as long. In almost all cases, a solitary naked mole rat is a disperser http://pacscilife.blogspot.com/2010/02/disperser-morph.html who has left his or her colony of birth and is seeking to join or found a new colony. Given an opportunity to be in a colony, they will try, despite the risk of being rejected or harmed. Colony life allows the animals to pool digging, food gathering, pup rearing and defense duties, as well as providing the all important cecotropes http://pacscilife.blogspot.com/2010/04/cecotropes.html without which the animals cannot digest their cellulose rich diet.

    Guests often ask if naked mole rats make good pets, but keeping an individual alone would put physical and behavioral stress on the animal and perhaps significantly shorten its life.

  20. Thanks regarding the post. It's good to listen to one other individual's opinion. I certainly agree with exactly what you are saying regarding the data. Please keep up the nice work as I'm definitely going again to read more.

  21. Awesome stuff, thank you and keep coming with these, will be back again.

    Kind Regards,

    Colin Seal
    describes it