herding
1. [ adjective ] (of birds and animals) tending to move or live together in groups or colonies of the same kind
Synonyms: social swarming
Examples:

"ants are social insects" "the herding instinct in sheep or cattle" "swarming behavior in bees"

Related terms: animal gregarious
Similar spelling:   heartening
  Herdon
  Harding
  Herdman
  hearten
  Hardin