The characters are wasps from the devastated nest of Ys’drktha. The other survivors from the cataclysm are being held and tortured in the pits of the neighbouring Ak’thaan nest, being slowly dismembered and eaten by drone wasps or fed to the writhing masses of larvae.
There are many possibilities for adventure. For example:
# rescuing the survivors from Ak’thaan,
# discovering what really caused the cataclysm which destroyed their nest,
# avenging themselves on the Destroyers (who ever they might be).
Roleplaying wasps might be difficult, but it means the PCs can fly and attack with stings (allow biting and leg-to-leg combat in case the sting is severed). It would be interesting to see what kind of characters developed from this role-reversal where the typically evil wasp becomes the hero.