diff --git a/agent.cc b/agent.cc
index dedd512..f82065c 100644
--- a/agent.cc
+++ b/agent.cc
@@ -4,6 +4,7 @@
 
 #include "agent.h"
 #include "connection.h"
+#include "main.h"
 #include "map.h"
 
 void
@@ -36,5 +37,5 @@ agent::on_tick(void)
 		tile->tile_in_dir(0, 1).symbol(),
 		tile->tile_in_dir(-1, 0).symbol(),
 	};
-	conn.senses(around);
+	conn.senses(tick_id, around);
 }
diff --git a/connection.cc b/connection.cc
index 3a6f0a4..0a467c7 100644
--- a/connection.cc
+++ b/connection.cc
@@ -7,9 +7,9 @@
 #include "connection.h"
 
 void
-connection::senses(char around[4])
+connection::senses(int tick_id, char around[4])
 {
 	char buf[1024];
-	snprintf(buf, sizeof(buf), "around %c%c%c%c\n\n", around[0], around[1], around[2], around[3]);
+	snprintf(buf, sizeof(buf), "tick %d\naround %c%c%c%c\n\n", tick_id, around[0], around[1], around[2], around[3]);
 	write(fd, buf, strlen(buf));
 }
diff --git a/connection.h b/connection.h
index 7d8f9e9..3067188 100644
--- a/connection.h
+++ b/connection.h
@@ -11,7 +11,7 @@ public:
 
 	connection(int fd_) : fd(fd_) {}
 
-	void senses(char around[4]);
+	void senses(int tick_id, char around[4]);
 };
 
 #endif
diff --git a/main.cc b/main.cc
index 7f5ae88..83f600a 100644
--- a/main.cc
+++ b/main.cc
@@ -10,8 +10,11 @@
 
 #include "agent.h"
 #include "connection.h"
+#include "main.h"
 #include "map.h"
 
+int tick_id = 0;
+
 int
 main(int argc, char *argv[])
 {
@@ -37,12 +40,14 @@ main(int argc, char *argv[])
 		class agent agent(0, agentpos, conn);
 
 		while (true) {
+			std::cout << "tick " << tick_id << '\n';
 			map.print_map();
 			std::cout << '\n';
 
 			agent.on_tick();
 
 			usleep(1000000);
+			tick_id++;
 		}
 
 		/* TODO: destroy agent cleanly */
diff --git a/main.h b/main.h
new file mode 100644
index 0000000..487982c
--- /dev/null
+++ b/main.h
@@ -0,0 +1,6 @@
+#ifndef BRMLIFE__MAIN_H
+#define BRMLIFE__MAIN_H
+
+extern int tick_id;
+
+#endif