Hungry penguins chase Antarctic's shifting krill
https://www.youtube.com/watch?v=UIW_4xR5OwQ 2:50 krill also seek refuge by forming a dense ball which makes it harder for small fish to find a target but allows the blue whale to gorge.オキアミも魚から捕食されないために一団となって行動すが、鯨はオキアミの塊を丸呑みにする。
Wonders of the Deep Blue Sea