would these help keep thier nails short, or simply hurt thier feet?

[Celestrina]

How safe are these for rats?  http://www.petsmart.com/global/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524441808017&FOLDER%3C%3Efolder_id=2534374302047590&ASSORTMENT%3C%3East_id=2534374302023691&bmUID=1155184815967&itemNo=19&Nao=12&In=Bird&N=2047590&Ne=2

[moonsingingfreak]

I can't imagine that it would hurt their feet unless they spent a LOT of time on the ladder. Beyond that I have no idea 

[Dork123]

Yeah, I doubt that would be a problem for their feet.  Rats are clever li'l things-- I'm sure if it is too rough of a surface for them, they'll simply stop using it.  The only thing I wonder about is if it would actually trim the nails at all....  I think they climb ladders like we do (with the center of their feet taking the most pressure).  It couldn't hurt to try it out, though. 

[Amykins]

It couldn't hurt to try it, but I haven't bothered with anything like that.  I simply trim their nails, even if it is a mini-battle everytime.  I have one boy who SQUEALS when he even spots those clippers!  hehe!