一利一害[ichiriichigai] advantages and disadvantages
煙害[engai] smoke pollution
加害[kagai] assault
加害者[kagaisha] assailant
禍害[kagai] evil

害悪[gaiaku] harm
害虫[gaichuu] harmful insect
害鳥[gaichou] vermin
害毒[gaidoku] harm

鼺鼠[momi] giant flying squirrel (Petaurista leucogenys)
鼯鼠[momonga] small Eurasian flying squirrel (Pteromys momonga)
熬海鼠[iriko] dried sea slug
海鼠[namako] sea cucumber (Holothuroidea spp.)
栗鼠[risu] squirrel (excluding flying squirrels)

どぶ鼠[dobunezumi] brown rat (Rattus norvegicus)
黒鼠[kuronezumi] black rat
鼠の嫁入り[nezuminoyomeiri] light shower
鼠疫[soeki] plague