Can't let the audience see them casting a Spell, with the glow of magic. This is a mundane world, even though there's no restriction on magic, attacking wild wolves doesn't count as against humans or illegal.
Luo Youyou didn't want more people in the livestream seeing her use magic.
Also advised that Mo Jingyan shouldn't do that either, other Magic Artifacts couldn't be used. Shortly, they would use sticks or slingshots, and the daggers distributed by the show crew.
They inherently knew Martial Arts, wild wolves are nothing to them, soon they'll use sticks to fight the wolves, like wolf-bashing sticks.
That cave, in fact, had a small number of Vine Whips covering the entrance.
The wild wolves could paw at stones to seal the cave, and with snow outside, people would not discover the cave.
Actually, werewolves are quite fearful, as long as they know wolves are around, people hide in fear.
