The phylenes, apart from their sphere of existance, are indifferently in the plains, the mountains, and the forests as long as the climate is temperate (temperature between 14 and 30°) and less than three miles to the closest waterss.

They are generally in small group of 3 to 11 individuals. No one has met them in odd numbers.
That can happen. However, if that is the case, then it is not 'sedentary', but one in displacement - one waiting to join a group, one related to a magician or one on a mission.
However the last case is rare. The phylene is the most difficult creature of the 4th sphere to summon.

Again, few things are known of these creatures. Indeed, if a phylene senses they were observed, they disappear and settle elsewhere.