How does one say "stung by a bee" in spanish?

Question

Here is the sentence where I want to use it:

:

They were reading newspapers in the park until bees stung them.

I have this much so far:

:

Ustedes estaban leyendo los periodicos hasta. . .

Gracias, Harley.

Answer 1

Estaban leyendo periódicos en el parque hasta que las abejas los picaron.

Answer 2

Gracias, Javier.

Answer 3

Estaban leyendo periodicos en el parque hasta que unas abejas les picaron.

Answer 4

I think Marty's sentence is a little better than Javier's one

In this case is correct the use of "les" and not "los"