Pygmy Cory Feeding And Behavior?

Hi.i keep mine with my betta in a 70 litre.there are marbled hatchetfish too.i feed flake.betta pellets and algae wafers.mine never tightly shoal either.loads of hiding space.i also have seven shrimp too.

 

Corys are shoaling fsh but that doesn't mean they won't strike out on their own, or in smaller groups, as fluttermoth said.  No problems there.
 
As for the food, I would get them off frozen bloodworms quickly.  This is not a nutritious food, quite the opposite.  A nice treat once a week, but no more.  Freeze dried foods are not much good for bottom feeders as these foods tend to float and not sink.  Most sinking foods will be accepted, and these will contain the essential vitamins and minerals.  These are much better than upper-fish foods.
 
The shrimp pellets (Omega One is the brand I use but there are others) are a good one to use, and I have never known a cory species that didn't like these.  Mine also go after Nutrafin's tabs which have earthworm meal.  And I also use Omega One's Veggie Rounds; these are primarily intended for algae grazers but they contain meat and vitamins, and all of my corys and loaches love these too.  It is good to get two or three different foods, and alternate from day to day.  The corys will undoubtedly be attracted to at least one, and go from there.  For six corys, I would drop in one or maybe two of the tabs or disks, and 3-4 of the shrimp pellets, whichever you use, and only once a day.
 
Corydoras pygmaeus is a very inquisitive cory, and they like to browse all surfaces from the substrate, to wood to plant leaves, and right up to the surface. In an established tank, these surfaces have a biofilm that will be rich with microscopic life, and the corys will eat much of this.
 
I started out with a group of six mature pygmy corys a couple years ago, and I put them in my planted 10g on their own.  I now have more than 30 of varying sizes.  I do not bother with fry foods, but there is sufficient natural infusoria and such for many of the fry to eat.  I have seen very small fry sitting at one of the sinking pellet tabs, so your corys will quickly learn these are food.
 
Byron.