Fall Month: 1 
Night 
Clear Moon: 
For those most part, what this meter does is determines how fast your pack will heal after fighting battles. The higher it is, the faster they'll heal. To keep it up, you just have to do these simple things:
1.Feed Them/ Give Them Water
Now this a fairly obvious factor, considering if you don't feed your pet irl, then there will be some issues xD
But yes, feeding and letting them drink from the spring can help the pack happiness to rise.
2. Pack Affinity
Pack Affinity can help determine how happy your pack is as well! Wolves with good or Excellent Affinity make the pack happier. If the wolf's affinity is at Ok or below, it may be helpful to consider finding them a new home as well, or purchasing a Make Friends.
(Special thanks to Faded and Shining for helping me with this one ^-^)
Well that's all I have for now. If anyone has any more ways to boost pack happiness, let me know, and I'll add it ^-^
Kodiak said:
An overcrowded den doesn't affect happiness at all.Dominance does, making sure no two wolves have the same dominance count or they will fight.
