My fish don't appear to have any interest in newly hatched baby brine shrimp

[Herefishie]

I am fairly new to the hobby. I recently bought a little kit and some cysts to hatch BBS. They are hatching but when I put them in the aquariums, my fish don't seem to show much, if any, interest. Are they just too small and are they just meant for fry? I have Danios, rainbow fish, Tetras, gouramis, Corydoras & a betta. 

[Zenzo]

In my experience, it depends on the size of the fish. If a fish is 1.5-2" or smaller, they pretty much will go after the live baby brine shrimp. Larger fish may take less notice unless there is a cloud of shrimp when you first pour them in. Of the list of fish that you included, I have had adult bettas and most tetras eat the bbs. My corydoras will eat them if they end up towards the bottom of the tank. I have not tried bbs with danios, rainbow fish, or gouramis (although I am certain that fry from all of these would readily eat bbs). 

[Theplatymaster]

For me it mattered if the lights on the tank were on, if they were my fish love it, if not they cant see it.

[TOtrees]

It may be that your fish are simply expecting something else when you feed them, and want those (relatively) big pellets or flakes. 

If you feed a pellet at the same time as bbs, most fish larger than guppies will 100% gorge on the pellets, and will only start on the bbs after the pellet food is gone. 

Keep feeding bbs, and don't feed anything else when you do, for at least a couple hours. Remember that bbs will survive in fresh water for around 2-3 hours. So if you're not seeing any bbs in the tank an hour or two after you feed (or less), then even if you didn't see your fish nomming them up, that's what's happened. 

Another option is to give the bbs another 6-12hrs in the hatcher, so they come out (very) slightly larger, which might be preferable to your fish. 

[Guppysnail]

I use a coral feeder and spray the substrate for my corydora. They go crazy. My honey gourami love them and my celestial Pearl danios. 
Previous zebra danio betta,  and tetra loved them. If they have not been fed them until adults and I buy them it takes them time to realize those dust specks are yummy. 

[Patrick_G]

My Swordtails fly through the cloud of BBS like Blue whales gorging on Krill! 😁

 

[reefhugger]

I hatched bbs for the first time recently as well.  I have to laugh at myself for not comprehending the difference between bbs and frozen brine shrimp.  Geesh. So I've started a bit down the rabbit hole of raising some of them to a larger size for some of the fish.  I've learned much of the nutrition of bbs is due to the egg sac still attached which quickly declines as the critter grows.  Still researching if feeding them as they grow keeps the protein content high enough.   

I have rainbow fish which are still small, and they swarmed the bbs.   Guppies and fry, small tetras, platies and corys  consumed them as well.  The angel fish and mollies looked at me like I was joking.