Matthew Poole and continuators on Exodus 23:28

28 And I will send Hornets before thee, which shall drive out the Hivite, the Canaanite, and the Hittite from before thee.

Properly so called, as may be gathered from Ios. 24. 12. Deut. 7. 20. Hornets are of themselves very troublesome and mischievous, but these it is very probable were like those Egyptian flies, Exod. 8. 21. of an extraordinary higness and perniciousness. Nor is it strange that such creatures did drive many of these people from their habitations, for many heathen writers give us instances of some people driven from their seats by frogs, others by mice, others by bees and wasps: of which see Herodotus, Diodorus, Plin. Aelian, Iustin, &c.

He names these three people, either for all the rest, because they were the most potent about the time of Israels first entrance into Canaan, and gave them most trouble, or because these three were more infested with Hornets than the other Nations, as being more numerous and dangerous.