Rat Bite Study Shows Rodent Owes 'Success' To Gnawing, Chewing Abilities

By: Wynne Parry, LiveScience Senior Writer
Published: 04/27/2012 05:21 PM EDT on LiveScience

Rats and their close relatives, including mice, make up nearly a quarter of known mammal species. New research offers a clue to these rodents' success: their bite.

Rodents have evolved two feeding modes, gnawing with their incisors and chewing with their molars farther back in their mouths. However, they cannot do both at the same time.

Some, such as squirrels and beavers, have specialized in gnawing. Others, such as guinea pigs and porcupines, have specialized in chewing. Others, a group called myomorphs that includes rats and mice, have taken the middle road by staying flexible and adapted to doing both at different times.

To find out whether rats could out-bite other rodents, a team of scientists from the United Kingdom, France and Japan, used computer models to simulate the bites of rodents. They also wanted to find out whether it was the rat's skull shape or its jaw muscles that gave it an extraordinary bite; so they created virtual animals with characteristics from different biters, such as a rat skull with squirrel muscles.

Not surprisingly, they found that squirrels can more efficiently apply force with their bite muscles when gnawing than can guinea pigs, while guinea pigs can chew with their molars more efficiently than squirrels. This makes sense, considering that squirrels gnaw on a diet of nuts and seeds, while guinea pigs eat grasses.

But rats turned out to be more efficient at gnawing and chewing than the other rodents.

The results showed "the way rat muscles have adapted over time has increased their ability to chew more effectively than a guinea pig and gnaw better than a squirrel, even though these two species are specialists in these kinds of jaw movements," study researcher Nathan Jeffery of the University of Liverpool said in a statement. "This goes some way to explaining why rats and mice are so successful, as well as destructive, as their versatile feeding behavior allows them to eat through a wide variety of materials efficiently."

The researchers detailed their work yesterday (April 27) in the journal PLoS ONE.

You can follow LiveScience writer Wynne Parry on Twitter @Wynne_Parry. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

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Comments

[LaoShur]

08:47 AM on 05/02/2012

"To find out whether rats could out-bite other rodents, a team of scientists from the United Kingdom, France and Japan, used computer models to simulate the bites of rodents. They also wanted to find out whether it was the rat's skull shape or its jaw muscles that gave it an extraordinary bite; so they created virtual animals with characteristics from different biters, such as a rat skull with squirrel muscles."

WOW, a team of "scientists"...I could have given you the same results through my experiences through my boyhood!

[AlonzoQuijana]

09:08 AM on 04/30/2012

I'd say omnivores have a big edge over specialized eaters, and the dentition of a rat is adapted to being an omnivore.

[webrat]

09:04 AM on 04/30/2012

hate these damn things. went camping with the kiddos and woke up with one of these fuc*s chewing its cud on my chest looking at me...

[AbstractImp]

08:41 AM on 04/30/2012

Hey, GOP membership is declining. . .
Can they driver hoverounds yet?

[erebus99]

08:02 AM on 04/30/2012

Lucky for us they don't have opposable thumbs.

[Santos-Dumont]

07:01 AM on 04/30/2012

They're able to find work with the Department des Vaterlandes Security.

[ennui the third]

06:54 AM on 04/30/2012

Like humans.

[evilchihuahua]

06:47 AM on 04/30/2012

I thought it was because 67 percent of the RNC's budget went for Purina Rodent Chow?

[Robert Frank]

06:46 AM on 04/30/2012

rats are smart and cool...I like them better than most people ..in fact I like all animals better than most humans

[SecularAdvocate]

07:41 AM on 04/30/2012

That's a classic sign of having been abused as a child, just in case you find that information in any way interesting.

[limonista]

08:05 AM on 04/30/2012

You are totally incorrect! Abused? Lol.

[gavrielle]

08:06 AM on 04/30/2012

And there you deliberately continued the abusive behavior, reinforcing the poster's dislike of other humans - just in case you find that information in any way interesting.

[limonista]

08:07 AM on 04/30/2012

There are some great people out there, but then I read what cultist "secular advocate" wrote. I now agree with you 100%.

[75thRangers]

06:45 AM on 04/30/2012

I thought this was going to be a story about the ,tea bags

[karen lyons kalmenson]

08:12 AM on 04/30/2012

steep

[gdauth]

05:16 AM on 04/30/2012

There may be some hope for Republicans after all.

[BLambda]

06:32 AM on 04/30/2012

Oddly enough there is no "RAT" in Republican but, wait for it, there IS a "RAT" in DemocRAT Just sayin.......

[apiazza]

08:54 AM on 04/30/2012

Similarily, there is no "CONSERVE" in conservative.

[JeanRR]

09:12 AM on 04/30/2012

Which is very the clever Republicans have lost the ability to say "ic". They like to emphasize the "rat." Aren't they just so cute?

[Fugitaboutit]

05:02 AM on 04/30/2012

The headline reads "Why Rats Have Survived." Simple. The Republican Party needs to keep its numbers up.

[waldopepper]

04:40 AM on 04/30/2012

Research grant money well spent.

[PsychicTuesday]

05:14 AM on 04/30/2012

They used computer models to run the simulations, so I doubt it cost very much.

[adamben]

03:43 PM on 04/30/2012

you have to buy computers, and soft drinks.

[one1byke]

06:18 AM on 04/30/2012

....you hate science, don't cha?!

[waldopepper]

11:34 AM on 04/30/2012

Read some of my posts. I hate religion. But most of all I hate those who jump to unfounded conclusions.

[Rich Cash]

03:46 AM on 04/30/2012

Well, duhhh....Anyone who owns a home that has been invaded by rats who have been able to crawl through a hole the size of a quarter shouldn't be surprised by this story.

[Tsvi1]

07:47 AM on 04/30/2012

Crawling through a hole and being better at gnawing and chewing than specialists in either aren't all that related....

[webrat]

09:53 AM on 04/30/2012

quarter? found a hole in my lake house that they had chewed through the wall about the size of a quart bottle. don't know if thats normal size for a hole. but i'm not really willing to meet or see the size of the rat that did it.

[anastomosis]

03:01 AM on 04/30/2012

When the human ape population crashes, as it will, it will be the rodents turn to succeed.
If for no other reason than all those rat dollars they'll save on dentists.