You set the frequency that you want rootshells to appear, and you set the amount of time that they will persist before backhoe deletes them. This gives the user who knows what to look for a convenient backdoor without having to modify any system binaries or otherwise fuck someone's box. Well, to make things more interesting, it also spawns multiple copies of itself, you know, in case root sees some strange process or behavior and decides to kill -9 the bitch. If any of the copies of backhoe find that any of the other copies are missing or not functioning, backhoe goes into defense mode.
Normal operation continues, with a few more instances of backhoe in memory.
Well, I suppose it could actually be useful for its intended purpose with an inexperienced sysadmin. Finally, run it just to see how it works, then make improvements. At this point, backhoe has only been tested on Linux. It definitely wont run on solaris as it is, mainly because of the flags on ps and parsing of the result set. This would be easy to fix by adding a random dummy process generator to spin the ps id counter in between spawns.