how long do your silk worms last?

Okay,
so I have beardie that is growing like I would like it to, and I have another that isn't eating as much as I think he should.

That being said, I decided to take leap and order a large variety of worms at once.I hadn't tried silks, so decided to. I order 25, and I got them on Friday. As of today, I have had six of them pass away. Yes, I am feeding them. The response I got when I contacted the place I ordered them from was, "most people feed them first and don't keep them".

I let them know, that I wanted to feed the worms to make sure they were good to go for my beardies and my beardies are pretty small compared to some of those silks, lol. The three dragons can't eat all 25 in one day..at least my three can't.

So that brings me to wondering... How long do your silks normally keep?
I want to make sure, what the place said was true and not just bad worms.

Thank you all for responses!

Two things about silkworms. They eat all day, every day, either prepared food or mulberry leaves. Second, they need to stay dry. No misting. No heat or cold. They aren't real hardy critters to begin with. Good luck!

Noelle