Draw calls dramatically increasing when instantiating prefabs on runtime

Hi all, I have create a script that generates levels on runtime by randomly placing prefabs.

If I manually place a single prefab in the scene and run the game it uses 10 draw calls.

If I instantiate the prefab using my script, the same prefab uses 394 draw calls. Im not doing anything clever in the script, just placing the prefab at a pre-determined location and making it a child of an empty gameobject.

Nothing seems to change on the prefab looking at it in the inspector, I just cant work out why the draw calls dramatically increase? Any ideas?

Ok, so after some googling, it seems that dynamic batching of instantiated prefabs doesnt work with deferred lighting, you need to change to vertex lit. All works fine now