When Crichton ask the others to sit with him to see if anything strange is happening on the ship, he later explains that he set one of the DRDs to record them. When he plays back the DRD's recording, towards the end of the recording, the playback changes camera angle, which would be impossible for a single DRD in a stationery position.
jool is a new crew member and is shown not knowing her way around moya. yet, somehow she makes her way to the starburst chamber on her own - a place john and pip had never been and even they were following a drd.