Causality is built into the Workings of the Universe

No chemical reaction/effect could occur if not for the fact that built into the workings of the universe and its construction is the lawful and regularly consistent process of cause and effect.

Causality is a natural law of the universe.

Observations of animals and infants demonstrate that they all anticipate this regularity in their world.  They anticipate an effect from a cause.
​
Pavlov's famous experiment of a ringing bell with dogs demonstrate that dogs anticipated this causal connection.  This demonstrates and proves that dogs are 'smarter' and know more about the workings of the natural world than David Hume.