Where does the term stand them on their ears come from?

The phrase "stand them on their ears" is a colloquial expression meaning to shock or surprise someone greatly. It's essentially a figurative way of saying "to make them jump" or "to knock their socks off".

There's no single definitive origin for the phrase, but it likely emerged from the idea that being startled or surprised makes someone feel unsteady or unbalanced, as if their ears are no longer securely planted on their head.

Here are some possible explanations for its origin:

* Standing on your head: The phrase might be connected to the physical act of standing on one's head, which would indeed feel unusual and unsettling.

* Hearing a loud noise: A sudden loud noise could cause a person's ears to "ring", making them feel disoriented and potentially causing them to lose their balance.

* Ear-splitting sound: The phrase may also be related to a "ear-splitting" noise or sound, which would be so intense it could make someone feel like their ears were going to be knocked off their head.

Ultimately, the exact origin of "stand them on their ears" remains somewhat obscure. However, the figurative imagery it evokes of being surprised or startled to the point of unsteadiness is clear.