A couple more...

In England (hundreds of years ago) thresh would be put down on the floors to aid in traction. Pretty soon the thresh would be spilling out the doors. So a board was installed to keep the thresh from falling out of the house. The board was known as a 'thresh hold'. Same as what is in your house now.

Also from England comes the phrase "its raining cats and dogs'. Houses there used to have thatch roofs which became very slippery when wet. Critters, including cats and dogs, would be up on the roof of houses. When it rained they would slide off. It was not uncommon to have cats and dogs pass a window during a rain storm.