Take to your heels
Definition 1 of 1
Pro Tip 1/3Urgency Implied
The phrase suggests an urgent and sudden action often due to fear or danger. 
Hearing the growl, we took to our heels.
Pro Tip 2/3Figurative Usage
Used metaphorically, not always implying literal running. 
At the surprise inspection, the workers took to their heels.
Pro Tip 3/3Informal Expression
It's an informal phrase, often inappropriate in formal writing or speech. 
In formal situations, instead of saying 'He took to his heels,' say 'He left abruptly.'