There are at least two instances of rats being impaled or sliced, however the rats are relatively recognizable as fake, even if one twitches, so it isn't likely to be as intense as depictions of animal abuse often can be.
R violence type: blood, gore and graphic.
A man is tied with chains with blood running down his face.
A man pricks his hand on a loose nail.
There is a graphic "rebirth" scene, which shows a man being reconstructed. Strong and gory.
A monster appears with no skin.
A man inserts his hand into people and sucks out their blood.
A bloody corpse is shown.
A man is sliced on his face by a knife.
A woman is stabbed in the stomach with a knife.
A man is pulled apart by chains
Three rats are shown twitching.
A rat is cut in half, bottom to top. We see the insides.