Weird Betta Fry?

[Suzie Q]

I was not sure where to post this. I have 14 to 15 betta fry left after a bug issue (see post in invertibra (sp?) "What the Hell is it"). Anyway I hatched brine shrimp for them (feed first bites right now), and they just looked at them. They would swim up to them...take a good look, them swim away. They are eating the first bites, everyone has a full belly so I am not worried. My question is...is this normal not to eat live food? I just hate wasting the brine shrimp (says not to feed to fry after 48 hrs because the yoke sack is used up...also says not intened to raise to adulthood. After about 72 hrs, all shrimp are dead)...I have to hatch so many that I only use 1/8 of the batch...if that many. Is it ok just to feed first bites...when do I need to feed them something different? I also found mesquito larva (not much bigger than brine shrimp) and I put the 3 smallest in there (the biggest fry would have had no trouble eating them) and they just looked at them...I needed to clean the bottom of the tank anyway, so I cleaned them out after 30 mins. All three were still in there.

I guess they don't like live food?!