A researcher at Montana State University has trained a dog to sniff out Knapweed, a noxious plant that can displace native plants and damge the surrounding ecosystem on rangeland. The dog will signal her finds by digging at the plants' base for a few seconds. A Global Positioning System device will track her during her search, noting the position at which she digs.
Terriers will be great at this job! :)
Source - April 2004 Dog Fancy
