diff --git a/src/main.c b/src/main.c
index 83a6712..e7d0e35 100644
--- a/src/main.c
+++ b/src/main.c
@@ -328,8 +328,9 @@ void handlePacket (int client_fd, int length, int packet_id, int state) {
             mob_y ++;
           }
           if (mob_y != 255) {
-            // Spawn passive mobs during the day, hostiles during the night
-            if (world_time < 13000) {
+            // Spawn passive mobs above ground during the day,
+            // or hostiles underground and during the night
+            if (world_time < 13000 && mob_y > 48) {
               uint32_t mob_choice = (r >> 12) & 3;
               if (mob_choice == 0) spawnMob(25, mob_x, mob_y, mob_z, 4); // Chicken
               else if (mob_choice == 1) spawnMob(28, mob_x, mob_y, mob_z, 10); // Cow