Well, first thing to do, is to confirm what the critters are. Could be ants. Or something else.

More than likely those are ant larva, not termites, but as Jean suggested confirm what you have and take the material back to where you bought it and get your money back.

Wood mulch does not attract termites; on the contrary, termites prefer a more higher nutrient woody material such as cardboard.

Still, you don't want such critters in your mulch, so while it is in such state, spread it out, and apply what will kill them. You might want to spread it out on a plastic sheet or something else so that the buggers cant escape into the soil to further produce young.

Identifying the critters is the first step before applying something to kill them.

It's entirely possible that they won't hurt a thing even if they survive.

And if they are ants, spreading the mulch will disrupt the colony structure. The ants will die without adding nasty chemcials to your immediate environment.