diff --git a/agent.cc b/agent.cc
index 438c234..05b7ad4 100644
--- a/agent.cc
+++ b/agent.cc
@@ -30,6 +30,11 @@ agent::move_dir(int dir_x, int dir_y)
 
 void
 agent::on_tick(void)
+{
+}
+
+void
+agent::on_senses_update(void)
 {
 	if (!conn)
 		return;
diff --git a/agent.h b/agent.h
index 7181c0f..3a77137 100644
--- a/agent.h
+++ b/agent.h
@@ -19,6 +19,7 @@ public:
 	bool move_dir(int dir_x, int dir_y);
 
 	void on_tick(void);
+	void on_senses_update(void);
 
 	~agent();
 
diff --git a/main.cc b/main.cc
index dab4017..14cf7fe 100644
--- a/main.cc
+++ b/main.cc
@@ -79,6 +79,11 @@ next_agent:
 		for (std::list<class agent *>::iterator agent = agents.begin(); agent != agents.end(); agent++)
 			(*agent)->on_tick();
 
+		/* Update agents' senses. */
+
+		for (std::list<class agent *>::iterator agent = agents.begin(); agent != agents.end(); agent++)
+			(*agent)->on_senses_update();
+
 		/* Finish a tick. */
 
 		map.print_map();