Hooks are not placed into the mold. The hook slot is to facilitate hooking the fish. By providing a "hollow" area in the bait body; the hook does not have to go through all the thickness of the bait. The slot also helps when rigging a hook in the bait as well. Other advantages are -- by thinning the amount of plastic ( with the hook slot ) you allow for a more active ( flexible ) bait and you enhance the baits weedless capabilities.