I think the birds will also eat the larve won't they?
At any rate I have never seen mosquito larve in a birdbath of mine. Plenty of other places but not in a birdbath.
I am a strong believer in the simple fact is that what matters in this life is how we treat others. I think that's what living is all about. Not what I've done in my life but how I've treated others. ~~ Sharon Brown