Mine does not try to hide it when in this type of mood - the whole office knows and dives for cover
We don't always know what has caused it but personally I try just to carry on as usual with him if I sense something wrong, but know when to keep a wide berth.
As Gee says, usually it is pressure from above and they just work it through.
I think the girlies in the office are more sensitive to bad moods than the men folk - I can tell the way the door opens in the morning as to what type of mood boss is in even before I have looked at his expression. A bit of stroking goes a long way in making my life easier, cup of tea, biscuit and top ups without being asked usually helps - much like being at home really
