Related Clues:

• Given appropriate backing, are prolific
• On a skip, will be plentiful
• Abound with and you gather up
• Meet up stream
• To pour with rain will be fitting on the way up
• Be rich? There must be a limit
• Gather up in swarm
• Heard 11 or 15, say, are full
• Back fitting to bear fruit
• Move in large numbers, having suitable backing
• Beat down group by the sound of it
• Swarm to gather up
• Be fruitful as side, according to report
• Rain heavily, upsetting assembly
• Sound of collaborative group in swarm