If a sensor exists to interrupt the current task for one of a higher priority then Subsumption agents may pursue the new task. But if not, subsumption agent behavior may not be salient because they lack an internal model of the world from which to make conclusions. It is debatable whether or not Subsumption Architecture is adequate. The response is limited to reflexive repertoire of actions. Like many of the insects that motivated their design, have a rapid, reflexive response to their environment.
Reflexive response is a necessity in a complex, dynamic environment.
The lack of a world-model means that its responses are always and only reflexive. The pre-wired connections require changing the hardware to change an agent's task. Since they are based on the behaviors of insects, subsumption agents exhibit many similar behaviors. Navigation is typically accomplished by several layers. The combination provides a simple way of getting from point A to point B without any explicit path planning.