“ A local fungus-breed explodes if hit or fallen upon. If there is any conflict between inteligent enemies,both sides are likely to use it to their advantage.”
“ Rich Romans raised fish in private pools at their villas. A favorite fish was lamprey, a parasitic fish which sucks off blood and flesh but made an excellent meal. A particuarly gruesome punishment for slaves was to be thrown into the lamprey pool, where their flesh was ripped from the bone by swarms of the jawless fish.”
“ A city is being plagued by a swarm of winged mice. The vermin can get anywhere, and they can easily avoid their normal predators by simply flying away from them.”
