diff --git a/controllers/sheep/flocking.py b/controllers/sheep/flocking.py
new file mode 100644
index 0000000..eb26f4f
--- /dev/null
+++ b/controllers/sheep/flocking.py
@@ -0,0 +1,30 @@
+"""Backwards-compat shim — flocking logic now lives in ``herding.flocking_sim``.
+
+Kept so any external reference still resolves.
+"""
+
+import os
+import sys
+
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_PROJECT_ROOT = os.path.normpath(os.path.join(_HERE, "..", ".."))
+if _PROJECT_ROOT not in sys.path:
+    sys.path.insert(0, _PROJECT_ROOT)
+
+from herding.flocking_sim import (  # noqa: F401
+    MAX_SPEED, FLEE_SPEED, WANDER_SPEED,
+    WALL_MARGIN, WALL_HARD_MARGIN, WALL_HARD_GAIN,
+    FLEE_DIST, SEPARATION_DIST, COHESION_DIST,
+    PEN_MARGIN,
+    compute_heading_speed,
+)
+from herding.geometry import (  # noqa: F401
+    FIELD_X, FIELD_Y, PEN_X, PEN_Y,
+    in_pen,
+)
+
+# Original module-level names retained for any code still importing them.
+X_MIN, X_MAX = FIELD_X
+Y_MIN, Y_MAX = FIELD_Y
+PEN_X_MIN, PEN_X_MAX = PEN_X
+PEN_Y_MIN, PEN_Y_MAX = PEN_Y
diff --git a/controllers/shepherd_dog/strombom.py b/controllers/shepherd_dog/strombom.py
new file mode 100644
index 0000000..a89d8c8
--- /dev/null
+++ b/controllers/shepherd_dog/strombom.py
@@ -0,0 +1,18 @@
+"""Backwards-compat shim — Strömbom logic now lives in ``herding.strombom``."""
+
+import os
+import sys
+
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_PROJECT_ROOT = os.path.normpath(os.path.join(_HERE, "..", ".."))
+if _PROJECT_ROOT not in sys.path:
+    sys.path.insert(0, _PROJECT_ROOT)
+
+from herding.strombom import (  # noqa: F401
+    F_FACTOR, DELTA_COLLECT, DELTA_DRIVE,
+    compute_action, compute_action_debug,
+)
+from herding.geometry import (  # noqa: F401
+    PEN_X, PEN_Y, PEN_CENTER, PEN_ENTRY,
+    in_pen,
+)