navmesh and randomly generated map

hey all,
i'm really fresh to everything unity and coding and whatnot, and i've watched a turtorial on a randomly generated map.
basically, i have a bunny i want to be able to run around my forest but she can't find the navmesh because i isn't baked into the world. her forest is randomly generated and so the game doesn't bake the mesh until after all the tiles have already spawned. Can someone help me delay the mesh baking for a moment so my bunny can explore her forest?