en_tn_lite_do_not_use/psa/078/045.md

swarms of flies

so many flies that it looked like a cloud

that devoured them

The flies made the Egyptians almost as unhappy as they would have if they had eaten the Egyptians. (See: rc://en/ta/man/jit/figs-metaphor and rc://en/ta/man/jit/figs-hyperbole)

destroyed them

"overran their land" or "went everywhere in their land"