He's 5 now and takes used tissues out of the bin, or iff DSes have left them lying from surfaces and eats them.
When he was a puppy he was a horrendous chewer, chewed everything from socks to plasterboard, wooden skirting boards and books. This all stopped when he was about 18 months, but the tissue thing has remained constant.
is it usual, or is it a Border Collie trait?