An entomology question

[Uncle Jesse]

The photo below is from the birdbath in my back yard, a "standard" cast concrete birdbath. I try to change the water every couple of days to prevent mosquitoes from raising in it, I frequently see wiggletails in the water before I wash it out. Recently I noticed what appeared to be small clusters of bubbles on the surface, when there was no reason for bubbles to be there (See photo). My question is ?Are these mosquitos? eggs?
Mosquito eggs 3.jpg

[Betty Hiner]

Mayhaps the beginning of some toads?? You know any Swamp Witches? Hummmmmm...?

[aged_sage]

No. They are neither mosquitoes nor their eggs. Their eggs are dark gray/black and are laid in small rafts that look like a very small grain pf rice. If you have any algae growing on the bottom of the bath, even just a green film, the bubbles could possibly be bubblres of oxygen produced by the algae during the day, when oxygen is a by-product of their photosynthesis. Just a guess!

[Fishingfiend]

The raft Aged Sage talks about looks almost like a honey comb, when looked at through a good magnifying glass. Most people never see skeeter eggs. I agree, also, with Sage's explanation of algae outgassing. Do you scrub out the nook and crannies when you change the water?
But there's also the possibility of ghosts. Tiny ghosts peeing in the water.

[Uncle Jesse]

I clean the algae a couple of times a year, I could not think of anything but mosquito eggs because I do see wiggletails in the water after about 3 days. I wash them out on the fallen leaves that cover much of my yard. I hope that does them in. My wife wanted me to stop using dunk because she read somewhere it might not be good for the bugs. Me, I think kill mosquitos first worry about birds second.

[Fishingfiend]

I've never seen mosquito larva blow bubbles in the water, but I suppose it could happen. If there's a film of some sort on the water surface, then the larva could be causing the bubbles.
I am thinking of the birds first, though, when I say this. Any poison (I don't know what "dunk" is) that is designed to kill bugs could be dangerous to birds. We are talking about a bird bath, so if you aren't thinking about the birds first, maybe you should jsut get rid of the birdbath ... no?