If Weedle are the assassins of the pokemon world, then Furret are the spies. They burrow silently through dirt and sand, or even stone and brick, leaving behind tunnels too narrow for other pokemon to pursue them, or even to notice. They escape easily, for they run through the underground as though it was a vast and endless plain. Although known as spies, they are common enough that the insufficiently cautious will take no note of their presence. And their senses are remarkably keen, allowing them to detect danger and likely even hear enough to report back everything needed, if only they could speak.
It is, of course, only with the invention of portable voice recording technology that Furret began to be employed for espionage. In the old days, human spies or Chatot were used, but it was difficult to disguise Chatot as Pidgey, and humans were often detected and killed – or worse for their employers, captured and turned double-agent.
Outside of Orre, of course, Furret have none of these weaknesses, just one enormous one. Furret have small lungs, and it is this which makes the narrowness of their tunnels often prove to be a tragic double-edged sword. If the tunnels they dig cave in, Furret will usually be unable to dig back to the surface in time. Instead, they die of asphyxiation, their knowledge and incriminating tapes lost with them. This is why those who suspect they are being watched always teach one of their pokemon Earthquake. The truly paranoid, such as Team Rocket's Giovanni, also teach them Fissure.