The Border Terrier likes to chew, reducing even the toughest of toys to piles of fluff with no effort. It is a good idea to invest in chew toys that are geared toward safe, heavy duty chewing.
http://www.petguide.com/breeds/dog/border-terrier

Chewing is something that all puppies do, but Border Terriers may carry it just a bit farther and some never really outgrow it.
http://www.btcoa.org/research/btbrfsec6.htm

Border Terriers also love to chew as all dogs do, but because of their breeding, Borders never seem to outgrow their need to chew.
http://www.petguide.com/breeds/dog/border-terrier