Locust heads turning black - safe?

[StarsNSand]

After around 2 weeks the heads of locusts will always turn black.
the body also starts to darken then they die
is it still safe to feed them to a pacman frog?
I've found no info online except a forum somewhere else and the person said they asked their shop owner who said it is caused by parasites, is that actually true??
Happens every time so I find it hard to believe.

[StarsNSand]

I found out the answer (hopefully) so if anyone wondered. I asked the shop where I buy them and was told it's because of environmental change. They are safe