Here is one idea:
Predators -> Scavengers: Scavengers are eating the meat/bones of the dead creatures [so basically when a scavenger spots corpses and body parts it will try to consume it].
Maybe it'd be better if we defined all these as tokens.
[DIGGING] - Nebulous, as we don't know what would be the best way to do it.
[NEST_BUILDER: MATERIAL] Animal constructs nests out of the given material, stealing it from the local environs; their young congregate there, and eggs are placed there. Said nest is destroyed annually, and can be deconstructed by dwarves for the material. Maybe this could be open-ended, so you could have troglodytes making rock nests, or some horrific monster making bone nests...
[BLOODLUST] Is attracted by blood on the ground/in the water.
[SCAVENGER] What Tormy said.
[WATER_JUMP] Swimming creatures will jump out of the water, creating a splash. Could be applied to magma swimmers for some scary results...
[SINGER:(TYPE):#1:#2] The creature will make a noise with a faint radius of #1 and a full radius of #2. Dwarves who hear within the #1 radius will get a small happy thought from "hearing a (type) (animal) song". On-break dwarves or children will, if possible, move to get within the #2 radius and get a greater happy thought from "listening to a (type) (animal) song". This tag could go on some vermin, like birds, and could possibly be used to make some deadly "siren" creatures. The (type)s could be stuff like "cheerful", "lilting", "melancholy", etc.
[NEST_HOARDER] - Goes along with NEST_BUILDER; the creature will steal items and put them in its nest.