Bunnies in dropship glow when there is fire at certain points on the map, just like how the Robo bunny glows when there is fire at his base.
Additionally, the Robosaru player can hear squeaks from bunnies at his base. Not sure if you want to fix this, it's a pretty cool way of enticing a Robo to waste his sentry charges, especially if you are behind him and already wearing a collar