Clearly we need camouflaged landmines. Double-plus bonus if they're shaped like potted plants and can walk on their own.
They make good trade goods, those landmines. Historically, I lost more of my citizens to landmines than those things ever killed enemies - be it soldiers or bandits. Meh. <sings> "where have all - the flowers gone .... loooong tiiiime passing" (look it up if you're too young to remember it).
Check this verion out pretty cool. NB: Landmines always kills a lot more civilians than soldiers, that why better export than use