Instead of set "lairs," have the odd WB attack randomly in a random place in a zone. Scare the begeebus out of unwitting or even witting players.
There'd be some subtle audible (the birds or insects stop chirping etc) and visible (bushes rustling) cues but you wouldn't know if it was an actual attack coming. Get the hair standing on end. Plug more excitement into the game so not everything is so static in the world. It also means you will have to work to hunt them down for the achievements. You could have the more sentient ones like the Cathay-raht in NE hunting you!
Anyway just an idea I thought I'd put in. Carry on.
Cheerio.
Gruumsh, Gruumsh, Gruumsh, Gruumsh, Miiighty Gruumsh!