群れる

1. Origins, structure, and basic meaning

• Structure: 群れる is read むれる.
• Basic usage: It means gathering in a group or flock.

2. Common pitfalls and similar expressions

• Schools of fish
  • 小魚が群れて泳ぐ: small fish swim together in a school.
• Where birds gather
  • 木に群れる: birds gather in a flock in a tree.