[BR the Betta]

few of these swimming around. Quite wiggly like a detritus worm but thicker and about 1/4” Long and will skim the glass. Looks like they have a tail fin, hard to tell. I want to say they are a larvae of some type. I thought mosquito at first but I don’t think that is what they are. hydra? do they get that big?

sorry, best image I could get

 

[Griznatch]

Yours Look like planaria, but the image is fuzzy. Hydra look more like microscopic stick-like anemone.... and they don't move much

 

[BR the Betta]

Should’ve mentioned they are not planaria. Pretty sure they are mosquito larvae. Makes sense since we leave our door open when it’s cool outside. I have had them in my water change bucket, just nit last couple of times. My betta loves them.

 

[Griznatch]

That's better than planaria , as long as the fish eats them and you don't get home grown mosquitos.

 

[ichthyogeek]

Probably mosquito larva. Does it look like this?

mosquito larvae - Google Search

www.google.com

 

[Plinkploop]

My initial thought was planaria as well, but if you've had mosquito larvae in your water it's most likely that, especially if your betta love them. I know mine hated planaria. Just wish you luck on those itchy bites if you have any grow out!!