> - - -
> Has anyone else seen tiny gnaw marks on bone buttons, handles
> (toothbrushes) and such...from rodents?  I wonder how common this  
> is, in
> dumped refuse?
>
> Also noticed this on hard rubber 'irrigators' (douche and enema tubes)
> from a privy.  The bone, I can see the critters wanting calcium, or
> something...but rubber??


This is extraordinarily common.  All members of Rodentia, as well as  
the Lagomorphs (bunnies, hares, rabbits), instinctively gnaw on  
almost anything.  It does not have to be food.  They must gnaw to  
keep their teeth sharp and the correct size.

"Despite their morphological and ecological diversity, all rodents  
share one characteristic: their dentition is highly specialized for  
gnawing. All rodents have a single pair of upper and a single pair of  
lower incisors, followed by a gap ( diastema), followed by one or  
more molars or premolars. No rodent has more than one incisor in each  
quadrant, and no rodent has canines. Rodent incisors are rootless,  
growing continuously. Their anterior and lateral surfaces are covered  
with enamel, but their posterior surface is not. During gnawing, as  
the incisors grind against each other, they wear away the softer  
dentine, leaving the enamel edge as the blade of a chisel. This "self  
sharpening" system is very effective and is one of the keys to the  
enormous success of rodents."

If I didn't see gnaw marks at all on a site, I would have a soil  
sample checked for toxicity.
Cheers,
Tim

Quote from:
http://animaldiversity.ummz.umich.edu/site/accounts/information/ 
Rodentia.html


Timothy Scarlett
Assistant Professor of Archaeology
Department of Social Sciences
Michigan Technological University
[log in to unmask]
(906)487-2359 (office)
(906)487-2468 (fax)
------------------------