Tunnel sense

A communication through small, inconsequential objects. Ratfolk use it to send small messages relating to the state of the tunnel, the mood of the tunnel's owner, or the latest cryptic love message.

The name tunnel sense was invented by a ratfolk who was not willing to divulge where they got their information from but needed to warn her non-ratfolk companions. Over time, the running joke amongst the ratfolk about "tunnel sense" became the best-known word to describe this method of communication.

Oh, you know... us ratfolk just have a tunnel sense.

— Pin, a female ratfolk who supposedly first came up with the name

Tunnel sense consists of the placing of items, or less commonly, markings, on any number in or around a tunnel:

• on the way to the tunnel
• on the entrance

• at an intersection
• at an exit/door

The items used typically consist of small mammal bones or insect husks, pebbles, sticks, loose threads, and tufts of hair. The fact that most of these items are lightweight and will be blown away or unintentionally moved is precisely why ratfolk use them. The messages being conveyed are meant to be temporary, addressing a current situation. It also avoids drawing suspicion to the placement of these items in the tunnels, since it is not uncommon to see these kinds of items and others, as "rubbish" along the tunnels.

Markings are preferentially avoided, since they remain in the tunnel for a long time, and can make non-ratfolk suspicious. However, when something is deemed important enough and long-lasting enough, ratfolk will etch a marking to warn other ratfolk.

Oh no, we really do not want to be using that tunnel to cross into Emerald City, believe me.

— Irram, a ratfolk trying to guide Padauk'ha into Emerald City

On tunnels and ratfolk

Ratfolks often build tunnels, even when living in cities. A common reason not to allow ratfolks for living in an area, was in fact, the fear that they would build tunnels all over the place.
Over time, some of these tunnels have become common knowledge and usage, and some cities would not even be much of a city if it were not for the tunnels connecting the different parts.
However, ratfolk have kept many of the tunnel secrets to themselves and may communicate these secrets to other ratfolk passing by through signals, known as tunnel sense.

Common Phrases

A tuft of ratfolk hair

This tunnel is in good condition

A tuft of ratfolk hair weighed down by a pebble

This tunnel sees lots of traffic

Three parallel sticks

House's owner is not receiving people

A pebble with a thread across it

I miss you (the colour of the thread indicates to the other person that the message is for them)

An engraved vertical bone

Danger!