ants in one's pants, have

have ants in the/(one's) pants

1. To be unable to sit still, due to anxiety, excess energy, or impatience. The kids really have ants in the pants today, so I'm going to take them to the playground. A: "Why is Carrie pacing?" B: "She's waiting for her doctor to call, so she's had ants in her pants all day."
2. To be interested in or in pursuit of sexual activity. You've been single for a while now—don't you have ants in the pants yet?
See also: ant, have, pant
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

ants in one's pants, have

1. Be extremely restless, uneasy, impatient, or anxious, as in This child just can't sit still; she must have ants in her pants. This rhyming idiom calls up a vivid image of what might cause one to be jumpy. [Slang; 1920s]
2. Be eager for sexual activity, as in Bill's got ants in his pants for Rita. This usage is less common today. [Slang; 1920s]
See also: ant, have
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
See also: