40d:Animal trap

Animal traps are special traps used to catch live vermin or fish from the river, not (large) land animals. Creating an animal trap requires the trapping skill and not carpentry or metalcrafting despite the fact that they are constructed at a carpenter's workshop or a metalsmith's forge. You may want to build separate workshops or forges to construct animal traps if you do it large scale, for if you do not have an unoccupied dwarf with the trapping skill active, work will grind to a halt as your carpenters and smiths wait for the construct animal trap job to be finished before they can get to their tasks.

Animal traps are stored by default in animal stockpiles when empty or containing an animal. They can be used for trapping animals in two ways - either by defining a Capture Live Land Animal task at the Kennels (which usually results in Vermin being captured) or by building them as an Animal Trap.

When used via the kennels, a dwarf with the Trapping labour enabled will pick up an animal trap and head to a food stockpile. The dwarf will search for nearby vermin, and if he find one, bundle the animal into the trap and drop it, and it will then be retrieved by a dwarf with Animal Hauling enabled and dropped in an animal stockpile.

When used via the build menu, the traps are constructed by a dwarf with the trapping labour enabled, using either a wooden or metal trap created previously from a Carpenter's shop or Forge. Once constructed, examining it with q will allow you to set the bait to be added to the trap. Set traps can be baited with nothing (z, presumably the inactive state), meat, fish or a large gem (presumably for more intelligent creatures). Once placed and baited, you simply have to wait for an animal to walk in and trigger the trap. Traps are not guaranteed to successfully capture an animal, and it seems safe to assume that the quality of a constructed trap has some influence on the capture chance. The bait will be stolen if the trap fails to go off, but the trap remains set and simply needs rebaiting.

Once an animal is caught in a built and baited trap, the game will pause, zooming to the trap, and you will receive an announcement telling you what you caught. The trap will automatically be slated for removal, and one of your dwarves will deconstruct it and move the trap containing the animal back to the animal stockpile.

The sorts of small animal that these traps can catch aren't butcherable and provide no raw materials. Dwarves can tame them as pets, or if you leave them in the traps in the animal stockpile dwarves will occasionally come by and eat them. If your dwarves have a particular liking towards eating the vermin you catch, you might be unable to easily tame your vermin, as the dwarves will prefer to eat your vermin over almost anything else. To prevent this, you can forbid the vermin, but not the animal trap. This will stop the dwarves from eating the animal, but will not hinder your ability to tame it, since taming requires only that the animal trap be usable.