Traditional geomantic omen generally believes that there are snakes in the tomb as a good omen. The snake is an earthworm, and there are snakes in the tomb, which shows that the tomb has good feng shui and is a "land of living dragons", and the coffin should not be moved elsewhere. The snake in the ancestral grave is the soul of the ancestors, which also shows that future generations are prosperous. When future generations see a snake, don't hurt it. If you hurt it, something bad will happen. If the snake dies, it will be a sign of catastrophe.
However, there is another folk saying that there are snakes in the grave, which should be analyzed in detail. This should start with where the tomb is, who is buried in it and when.
But the above statement has no practical basis. I don't know whether it is true or not, but in the face of such a situation, I would rather believe it than pay more attention to it, so as not to cause unnecessary trouble and harm!