Is there a trait to make a unit not plunder trade routes specifically?

[Tychusfindlay919]

I'm trying to make a unique gaming experience with the zombie mode (I play with historic speed and more barbarians mod, so I either find a way to better balance zombies or it's just pointless playing the mode).

I was wondering if there was a particular trait within the available XML files that I can copy pasta in an update to the ZOMBIE UNIT so that they can't plunder trade routes.