That’s a little like throwing coke bottles at mosquitoes. You might hit a few, but probably expend all your ammo doing it. My understanding is that the reload time for a Phalanx gun battery is on the order of 5 or 10 minutes.
Still, it’s your only system that has any capability against that threat, so it should have been tried.
I’m thinking high powered microwaves or even UHF from a banana antenna bobbing up and down, turning left and right. Like the landing radars around military bases. Somewhere around 100kW or so.
The radar operators used to knock the pigeons off of hangers that way. Just sweep the sky. Don’t want any actual aircraft around though.
Yes, why didn’t ship commands use Phalanxes?