Lemming (noun)

1. A small Arctic rodent of the genus Lemmus and related genera, known for migratory behavior and mass movements in which large numbers of individuals move together in the same direction.
2. A person who blindly follows a leader or group without thinking for themselves.

Origin:

From old norse lemmingr, from lemja "to lure".

Examples:

1. The lemmings were migrating in large numbers.
2. The lemmings' mass movement is a common sight in the Arctic tundra.
3. He accused them of being lemmings, blindly following the leader.
4. The lemmings were known for their suicidal migration.
5. He felt like a lemming being swept along by the crowd.