these boogers will be paddling for their furry lives

[meliss]

"Tents alone, to house the throngs, will need a thousand camels just for transportation. The tally of mules is past calculation, as are the invoices already being sent in by their wranglers. How will we water all these beasts? The River Bactrus is home to hundreds of sacred otters. “By Heracles, these boogers will be paddling for their furry lives!”" (The Afghan Campaign by Steven Pressfield.)
Hi. I do not understand what will "these boogers" do (be paddling for): to defend themselves or to suffer?

 

[jutfrank]

The otters will be scared away by the vast number of animals that will be taken to the river to drink.

 

[teechar]

See also run for one's life:

Definition of RUN FOR ONE'S LIFE

to run to escape from great danger… See the full definition

www.merriam-webster.com

This is a common idiom in English.