If a toxic algal bloom led to the first plague, and a pile of dead frogs followed, it's not surprising that a swarm of insects of some sort would have followed. The answer, I believe, is clear.
In fact, there is a papyrus in the Leiden Museum in Holland which provides a graphic portrayal eerily reminiscent of the biblical account.
Pharaoh even sent investigators Exodus to find out if the Israelites were suffering along with the Egyptians, but the result was a hardening of his heart against the Israelites.
Anyway, with the swarms God made a distinction between His people and the Egyptians. But the Bible teaches that God will ultimately differentiate between His people and all others on this planet Revelation ; Revelation First Corinthians teaches that Jesus became our Passover when He died to deliver us from the bondage of sin.
They were very severe; previously there had been no such locusts as they, nor shall there be such after them.
As soon as the request is granted by the Lord, Pharaoh reneges on his promise and will not let them go, and continues to worship his Egyptian Gods. God commanded each family to take an unblemished male lamb and kill it.
The disease is thought to have originated in Asia, and traveled to Egypt 5, years ago along prehistoric trading routes, the New York Times reported in Isis is silent once again.
The account was one of dozens of similar anecdotes collected in "The Book of the Damned"though its somewhat skeptical author suggested that the frogs may have simply dropped from trees. The implication of the three lists of plagues is that Israel did not preserve the details of the plagues or their number for their own sake, but rather recalled the significance of the plagues as events demonstrating a theological principle.
However, when placed in the 12th dynasty under a revised chronology, there is substantial evidence for Israelite slave laborers in Egypt.