Exodus 8:18

And the magicians did so with their enchantments, to bring
forth lice
They made use of their magical art, and juggling tricks they were masters of, to produce the like sort of creatures, or at least to make such appear, or seem to appear, to the eyes of men:

but they could not;
God would not suffer them to do it, to impose upon Pharaoh, and deceive him and the Egyptians any longer; and a stop is put to them, when such small and despicable creatures were produced, the more to put them to shame and confusion, and to show that what they did before was not real, and that what they did in appearance was only by divine permission;

so there were lice upon man and upon beast;
these lay in great numbers on both, biting and distressing them in a most terrible manner; for as the magicians could not produce such creatures, it was not in their power to remove them.