The reaction of an organism to a stimulus will depend upon its motivation. A hungry animal and a starving one will generally respond differently to the presence of food. The hungry animal may not respond in the same fashion if it is presented with the food in a dangerous situation. Organisms often need to prioritise their behaviour in response to a simultaneous set of stimuli, which have different levels of importance to their continued survival. Motivational stimuli result in a drive towards carrying out a particular behaviour pattern, for example the change in day length through the annual cycle can increase or decrease the ‘drive’ towards sexual activity in many mammals.