This is due to server lag, it shouldn't do this but sometimes does depending on a combination of your internet and the server's ping.
The reason for this is the script walks to a tile but sometimes it may initially 'miss' this tile and so the script will walk to the 'wrong tile' despite this still awakening the crab. If the ping conditions are good then the walking method should shut off and it should continue attacking the crab, however sometimes the walking method continues to try and walk to the desired tile a second time.
apa
replied to your PM. in the future please only try and contact me though 1 medium