Need Help Identifying Small Moving Things

[Electrician4hire]

I have a 20 gallon, Freshwater tank setup. Its been up and running for close to 2 years. No issues at all, within the past few weeks i have these little things on the glass. They seem to move around. really slow. i tried to take a pic
https/drive.google.com/file/d/0B4AGo-cbSKpYWHlqZWp3Sy1FUXc/view?usp=sharing
It's hard to focus on them. this is the best i could do. hope this pic helps. any help would be greatly appreciated
 
I hope i posted this in the right place too

 

[betta fish]

Snails of some sort? difficult to say looking at the pic.

 

[Electrician4hire]

they are pretty much see through except for a tan or black spot in the middle. they dont seem to get any bigger. I have never seen any other snails in my tank other than my few nerites. Nerites shouldnt breed in freshwater correct?

 

[Ch4rlie]

Looks like will most likely be common snails as when very young they are almost transparent.
 
And yes, quite correct that Nerites won't readily breed in freshwater.
 
"The Tracked Nerite Snail requires brackish water in order to breed successfully. Some hobbyists have been somewhat successful in breeding nerite snails but it does not seem that the young snails survive for too long. Some may look at this as a plus, meaning that the Tracked Nerite will not over populate a tank and become another pest in the aquarium."
 
Quoted from -
http/www.planetinverts.com/tracked_nerite_snail.html

 

[Electrician4hire]

Thanks. i wish i could get a better closeup in focus. I guess maybe a couple assassin snails to help out the problem

 

[Liv15]

Freshwater Limpet - Acroloxus lacustris ?
http/www.planetinverts.com/what_is_that_bug_in_my_aquarium.html

 

[Akasha72]

if you add assassin snails they may try to take on the nerites. I have a lot of trumpet snails and I considered an assassin to keep then numbers down but I have two nerite snails and I was advised against adding any assassins if I wanted to keep my nerites 
 
http/www.fishforums.net/index.php?/topic/437509-zebra-nerite-snails-and-assassin-snails/

 

[Byron]

I cannot tell from the photo.  Snails and limpets are possibles, and both are harmless.  You say these only appeared in the last two weeks and not during the previous two years...was anything new added to this tank, thinking of plants or fish, recently?
 
Snails are harmless and very useful, so be thankful if you have snails.  They are your friends in a fish tank.  But to be honest, I am not at all certain the critters in your photo are snails, so I would recommend further research/photos to better ID them.
 
Byron.

 

[Electrician4hire]

I started noticing them in the past two weeks. they may have been in there longer. its been about 6 months since i added a few neon tetra. and before that about a year i added 25 red cherry shrimp. 

I have nerites and assassin snails in my 72 gallon and the assassins leave the nerites alone.
 
They do kinda look like limpets!!! how do i get rid of these?