Possible Clues:

• Investigate, and find a crawler has accepted cash
• Vet's power to open up tiny creature
• Examine prisoner initially arrested by bluebottle, say
• Look closely and you'll find it's six feet around the piano
• Coppers breaking in on a crawler to make search
• Look at 'P' breaking up the sound of 'B'
• Check fly, perhaps, having caught end of zip
• Check a little crawler carries small change
• A little crawler going round quietly to investigate
• Fly, perhaps, keeping pressure in check