Analysing - extract one

Tune for Bears to Dance to by Robert Cormier

In this novel, Henry works for a Mr Hairston, who runs a shop.

Read the extract below and answer the question on language features.

quote
"Potatoes to bag up," he called over the shoulder of a customer, and Henry made his way down to the cellar, where a bin of potatoes awaited him. He always tried to hurry the job because the cellar was dark and damp and he often heard rats scurrying across the floor. One day, a grey rat squirted out of a bag of potatoes and Henry had leapt with fright, his heart exploding in his chest. He was afraid of a lot of things - the closet door that never stayed closed in his bedroom, spooky movies about vampires - but most of all, the rats."
A rat escaping from a bag of potatoesA rat escaping from a bag of potatoes
Question

...a grey rat squirted out of a bag of potatoes...

(a) What is unusual about the writer's use of the word 'squirted' in this sentence?

(a) The word 'squirted' is usually associated with liquids and the rat's movement is being compared to liquid being forced out of a tube or a bottle. The writer has used a metaphor.