What does it mean to have a blackbird fly into the house?

This has no feng shui significance. I heard that there is a phoenix tree that can avoid hundreds of birds and make them afraid to nest or inhabit where it exists. This is a way to avoid bird droppings on buildings.

There is also the legendary phoenix tree, which can attract the phoenix, and the phoenix only lives on the phoenix tree. Because the phoenix is a treasure, this phoenix tree is also a treasure.

There is an old saying that night owls enter the house without exception, so owls are considered unlucky.

Swallow nesting is considered to be a family with a long history, because unless there is an accident, swallows will return to the nest built last year every year.

As for other birds, it doesn't make any sense to fly around the house. But everything is as it is, and everything in the world can be predicted.

Therefore, birds entering the house have no feng shui significance, but they can be divination, which will break things.

However, you didn't tell me whether the bird entered the house, or which direction it came from, or when it entered the house.

Especially the first point is the most important. If an alien bird enters the house, it must have fallen off. If they fly around the house, it is possible that the birds entered the house by mistake because of fright, so there is no significance and possibility of divination.