A system comprising: one or more Unmanned Aerial Vehicles (UAVs); and a UAV carrier configured to carry the UAVs from an origin to a destination; wherein the UAV carrier comprises a first controller configured to release the UAVs from the UAV carrier; and wherein each of the UAVs comprises: one or more motors configured to generate a lift, lifting the UAV; characterized in that each of the UAVs further comprises a second controller, configured to: activate at least one of the motors of the respective UAV after the release of the respective UAV from the UAV carrier and upon fulfilment of one or more conditions, thereby generating the lift, wherein after the release of the respective UAV and before the activation of the at least one motor of the respective UAV the motors of the respective UAV are inactive, and wherein one or more of the following options is fulfilled: (a) each of the UAVs further comprises an accelerometer, and at least one of the conditions is that readings of the accelerometer indicate that the respective UAV reaches a terminal velocity, (b) each of the UAVs further comprises an altimeter, and at least one of the conditions is that the readings of the altimeter indicate that the respective UAV reached a given altitude, (c) each of the UAVs has an armed state and a disarmed state, and at least one of the conditions is that the respective UAV is in the armed state, (d) each of the UAVs further comprises a distance sensor, capable of measuring a distance between the respective UAV and the UAV carrier, and at least one of the conditions is that the readings of the distance sensor indicate that the respective UAV reached a given distance from the UAV carrier. one or more Unmanned Aerial Vehicles (UAVs); and a UAV carrier configured to carry the UAVs from an origin to a destination; wherein the UAV carrier comprises a first controller configured to release the UAVs from the UAV carrier; and wherein each of the UAVs comprises: one or more motors configured to generate a lift, lifting the UAV; characterized in that each of the UAVs further comprises a second controller, configured to: activate at least one of the motors of the respective UAV after the release of the respective UAV from the UAV carrier and upon fulfilment of one or more conditions, thereby generating the lift, wherein after the release of the respective UAV and before the activation of the at least one motor of the respective UAV the motors of the respective UAV are inactive, and wherein one or more of the following options is fulfilled: (a) each of the UAVs further comprises an accelerometer, and at least one of the conditions is that readings of the accelerometer indicate that the respective UAV reaches a terminal velocity, (b) each of the UAVs further comprises an altimeter, and at least one of the conditions is that the readings of the altimeter indicate that the respective UAV reached a given altitude, (c) each of the UAVs has an armed state and a disarmed state, and at least one of the conditions is that the respective UAV is in the armed state, (d) each of the UAVs further comprises a distance sensor, capable of measuring a distance between the respective UAV and the UAV carrier, and at least one of the conditions is that the readings of the distance sensor indicate that the respective UAV reached a given distance from the UAV carrier. (a) each of the UAVs further comprises an accelerometer, and at least one of the conditions is that readings of the accelerometer indicate that the respective UAV reaches a terminal velocity, (b) each of the UAVs further comprises an altimeter, and at least one of the conditions is that the readings of the altimeter indicate that the respective UAV reached a given altitude, (c) each of the UAVs has an armed state and a disarmed state, and at least one of the conditions is that the respective UAV is in the armed state, (d) each of the UAVs further comprises a distance sensor, capable of measuring a distance between the respective UAV and the UAV carrier, and at least one of the conditions is that the readings of the distance sensor indicate that the respective UAV reached a given distance from the UAV carrier.