The present invention relates to a method for detection of a deviating behaviour of a milking animal (101) during milking procedure comprising a sequence in an automatic milking system (100), comprising a robot (105) having a process for positioning teat cups (106). The method comprising the steps of: obtaining an identity of said animal (101), retrieving information related to said animal 101 from a memory (111), said information comprising a reference value derived from a previous milking procedure sequence, registering a value, related to said robot (105), from the present milking procedure sequence, comparing each reference value with the registered value in an analyser (112), and issuing of a warning signal if any of said registered values deviates from the corresponding reference value more than a predetermined deviation value, whereby the process for positioning the teat cups (106) is used for determining if the milking animal (101) deviates from a normal behaviour. The present invention also relates to a device.