I knew of a school that had no "regular" science department other then the part time technician from the beginning of a school year. It should have had five or six teachers but instead it had; two long term supply teachers, a regular returning supply teacher (me) and then whoever the agency sent from day to day. There was never any work set for visiting supplies and the long term supplies, technician or myself would just guide them to the next page in the text book (since we had our own work to plan). But the school only had itself to blame. A previous weak head with a poor behaviour management policy meant that behaviour was dreadful. The school was well known on the supply circuit as the worst in the area . Many supplies wouldn't return after one visit and others refused to go there at all because of its reputation. To make matters worse the school had negotiated a special rate with the agency meaning the daily rate was lower then anywhere else and as work picked up as the school year progressed the supplies they had abandoned it for better pay elsewhere. But a new HT turned it around. He was more robust and streetwise then the previous one (ironically he was an ex-pupil from many years before). He introduced a tougher no nonsense behaviour policy and things improved dramatically within that school year. However the school still struggled at first to attract teachers (contracted or supply) because of its old dreadful reputation.