Agree with Paul except to say that all fish can taste food from outside their mouths, but especially on their lips in the case of chub.
So they tend to mouth the bait with just their lip, hence what appear as false bites because the hook on a hair rig hasn't gone insde the mouth. As he say above, tighten up the bait to the hook and you might catch more.
You can band the bait onto the hook in the case of a hard pellet or alternatively, try these new
Mistral Soft Dusted Halibut pellets side hooked. That way the hook's definitely in their mouth.
When they want the food all fish (including pike) are just a bunch of suckers.