Photographing groups is more of a challenge for me. Multiple people/animals just means more chances of something going wrong. There is bound to be someone looking the wrong way, or making an awkward face. Animals just do what they want pretty much and will not face the camera regardless of what you try.
However, if I just let the group be and not force something from them, I can get lucky and capture the mood, the emotion, the moment.
That is when group photography shows its power.