Keep in mind you could probably get pretty close in terms of sychronising clients via specifying a vector on the serverside every random x seconds for the bug's direction and duration to travel (could be stored in an attribute?), store the last x,y in other attributes and let the client handle the interpolation easing the load considerably compared to having to execute the script every frame or whatever the execution rate is on the server. Also I realise I've left out of a few details here in terms of players entering at different times, but surely such a scheme is achievable to offload a lot of work the server does on to the clients.