Dear Prof. Southwik, My experince in the desert of Israel is the same ,I've found about 40% of bees moveing to the wrong hive, Dr Kora Rosenthal, Mikhveret Zriffin, Minis. of Agriculture, Israel,she gathered the last 2 years data and I'm sure that she will supply you more information.all the best , Dan Eisikowitc h. (eisik,@taunos).