| Answer | Crossword Clue |
|---|---|
| run | migrate or move in considerable numbers |
| irrupting | (of a bird or other animal) Migrate into an area in abnormally large numbers |
| trooping | to gather or move in great numbers |
| troop | to gather or move in great numbers |
| filtering | Move slowly or in small quantities or numbers through something or in a specified direction |
| filtered | Move slowly or in small quantities or numbers through something or in a specified direction |
