Possible Clues:

• Built-up colony is unable to freeze when cold is completely kept out
• Many a worker here right to avoid an exciting experience
• Insect colony
• A rise for the workers?
• Built by the workers for relative heard in Croke Park
• Mound of earth formed by insects digging their underground nest
• A new work outside hospital in a mound of earth
• Everyone outside national organisation greeting result of workers' efforts
• 26 down might be the sort of female to be found there