Ugh! Usually this can happen during hot summer days when they sit on the trucks too long. But it sounds like they were too long unrefrigerated and unfed, or overheated or frozen. Definately let the vendor know.

If you can sift them out of the frass, that will help. Once when I had a batch where a lot of them were dead, I think I put something they could crawl on, like a paper towel or some lettuce leaves, and then took the live ones out that way (if they could crawl, they are alive).
Sometimes if there is a dead one or two in the feeder, it does go away. So either the birds ate it, or tossed it out (being polite as JanieMay might say). But I don't think you would want too many dead ones in there.
Feed the live ones, and then keep them refrigerated until needed, in a container with vent holes for air.
More info @Bet's web site:
Bluebars

Here is a link that might be useful: http://www.sialis.org/feeder.htm

It is a hazard to your health for sure. I use a metal screen type strainer to get the worms out of the frass. I had that happen from grubco too. They arrived the next day after I ordered them and at least half were dead. I want to know what he tells you when you call.
Cathy

Save the shed skins of the mealworms and put them out for the Mourning Doves. They eagerly eat the stuff!

I'm very fortunate to have a Wildbirds Unlimited 1/2 mile away. I'm probably spending more $$, but I know they will make it good if I have a problem. As a matter of fact, they order large quantities and then sort them and package them into 500 or 1000 cups right there at the store. I paid $15.00 for 1,000. How does that compare to other prices?

It's been my experience that the blues ignore dead ones. I'm glad to learn that mourning doves will eat them. I'll put the few that I do find under my finch feeders where the doves glean.

Ok, I called Grubco and they are refunding me a quarter of the cost of my original order - because that's about how many worms I told them I lost. The girl said that black dead guys means that they got too hot during shipping, but they were coming from Ohio to Delaware, and the northeast has been on the chilly side for the past week. Who knows. I know several folks said last week that their Grubco orders had been delayed due to high demand, so perhaps they're sending out whatever worms they can get their hands on to keep up and not screening as well as they usually would.

Dee - how funny about the doves eating frass. You know so much about birds, even strange esoteric stuff like that. I'll keep it in mind. As I've said before - nature doesn't seem to waste very much...

Blumz - I paid $20 plus $9.95 s&h for 5,000 worms. So even with the cost of the shipping and the dead worms, you are still paying twice as much. Then again, there's something to be said for not being nauseous all night because you had to spend two hours sorting through black oozy dead things. I think I'll try Sunshine for my next order and see if it goes a little better.

I just got mine from Grubco and it just doesn't look like I have 5,000 this time. I just checked them after seeing your post and there are many that are turning black. They weren't black when I got them yesterday, but they are turning black now. I immediately put them in bran when they arrived.
I don't think Grubco will do anything for you. Started around now they really have a hard time keeping enough mealworms on hand. I like Sunshine's customer service better, but I got 10,000 of large healthy looking mealworms from them earlier and they started dying too. That is not normal for me at all.
Tammy

One of our aviaries is a 12 ft. x 12 ft. x 12 ft free flight for our pet birds and some of the smaller unreleasables. We'll put out a tray with mealworms for the finches and whoever to eat. Our Ring-neck Doves go for the shed mealworm skins. We have an unreleasable Mourning Dove as well and that is his greatest treat. Seems to be the doves greatest delight. I've not seen them eat the actual mealworm.

When we get a huge number of mealworms we'll just scoop the shed skins off the top and put them on the patio. In no time the Mourning Doves come and clean it all up. I haven't seen any other bird other than doves eating the stuff.

I'm thinkin' it may be a calcium source? Must have some kinda nutrients they need.

I've always been pleased with Sunshine, except the packaging but I've learned to deal with that...my last order arrived last Thurs. 5/8...everyday, I see more and more dead ones...I did feed them on sat. 5/10 (I think)...is there any way to increase their life span?? They are perfect upon arrival, so I think I might be doing something wrong...

Donna

Since I don't have as many bluebirds as the rest of you, I can't buy those large quantities. Convenience is worth $$ to me. When I bought my last thousand in 1 large carton already packed in bran, I separated them into two 500 worm cups. As I stirred and separated them, it was apparent to me that I had gotten my money's worth - hundreds of healthy, juicy, wriggly worms. I could just see the BBs little beaks watering!

If I were you, I'd be really upset that so many of them are dead and dying.

Blumz..I'm feeding just one pair and now the fledglings...unfortunately, the only WBU store is about 90 miles from here...do they ship? I'd be willing to try them!

Donna, I don't know if they do or not. I know that each store is a separate franchise. Here is their website - I didn't see them on a quick scan. You might check it out.

http://www.wildbirdsunlimited.com/