There's no flies on
there are no flies on (one)
1. One is very active or works at a fast pace. Alludes to the idea that flies do not or cannot settle on fast-moving animals. There are certainly no flies on Judy. She works so fast that the rest of her team can't keep up with her.
2. One is not at all dull or dimwitted; one is exceptionally sharp or shrewd. In this usage, "there are" is often contracted colloquially into "there's." A: "My son keeps trying to get his little sister to do his chores for him, but she sees through his ploys every time." B: "I tell you, there's no flies on her." There are no flies on our boss. He always seems to be one step ahead of what the market is doing.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
There's no flies on someone
. Rur. Someone is full of energy and drive. There's no flies on Jane. She's up at five every morning, training for the big race.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.