Those cave bull images were Aurochs, the wild ancestors of modern cattle. The last Auroch died in modern times.
Our guide at the Lascaux cave (Lascaux 4) taught us that the early men in southern Europe (35-25,000 yrs ago) were not "cave men". At the time, southern Europe including southern France was tundra and grasslands while northern Europe was covered with the ice-age icecap. Those homo sapiens were dark-skinned, nomadic, stone-age hunters who mostly followed the reindeer herds for easy food, skins. My ancestors. Like me, liked meat.
I'm sure they used the limestone cliffs for temporary shelter but they did not live in the caves they decorated - art for unclear reasons.
I first learned about cave art in my art history course in secondary school. That was a life-changing course. I still have at least 3 unanswered questions: How did they practice their art before committing to a wall? Was artistry a specialty? And why very few images of humans?
Another wonder: Weren't these people cannibals? I thought they were.