How about a bot that goes around a path and can turn both left or right, like L or R, and keeps going in either direction. In other words as long as it sees a path ahead it can turn either left or right as required. Perhaps it needs a certain block to travel on, such as Stone only. Or it might be a different type of bot altogether that looks like a robot hoover you can buy. (A small round shape like a giant coin.)
How about a bot that goes randomly L or R, but always stops for a second or two before deciding which way to go next. Perhaps it only travels in one direction L or R for a set amount of time, say 30 seconds. Or how about bots that walk upside down, on the bottom of blocks. Would have been useful on my latest level!
The bot will travel for a while, say 1 or 2 minutes. Then stop to think where to go next for 1 or 2 seconds!
I've got it! A bot that keeps moving until it reaches a junction. Then it chooses to turn L or R randomly! Like this:
