Loitering weapon

Weapons that are capable of waiting over an area before they hit their target, are called loitering weapons. Other names include loitering munition, suicide drone or kamikaze drone. Kamikaze were Japanese pilots who carried out suicide attacks with planes, during World War II. Loitering weapons are more similar to a drone, but they also have some properties of a missile. In this type of weapon, the munition waits, until it detects a target, Sometimes, it waits until it is given a command to attack. Loitering weapons allow to select targets more precisely. 
They are different from cruise missiles because they are designed to loiter for a relatively long time around the target area. They are different from UCAVs in that a loitering weapon is intended to be used in an attack and has a built-in warhead. As such, they can also be considered a nontraditional ranged weapon. 
The first loitering weapons were built in the 1980s. At that time, they were used against surface-to-air missiles (SAMs). They were used to suppress enemy air defenses in the 1990s. From the 2000s, loitering weapons have been developed for extra roles such as relatively long-range strikes, fire support or tactical, very short range battlefield systems that fit in a backpack.
Ethical and international humanitarian law concerns.
Some of these weapons are capable of making decisions on whether to hit a target or not, on their own. If no human being is involved in this decision, this raises a number of ethical issues, and problems with international law. In many respects loitering weapons are not comparable to a missile, that is fired at a target. A loitering weapon may spend hours waiting for a target to appear. While it may request final clearance before the hit, this does not have to be the case. In other words: With a loitering weapon, there may be no human who decides what target is hit.