Are they fighting...?

[Elska]

I have an adult A. Gigas living together with a Dendrostreptus Macracanthus and I thought they could get along.
But sometimes the Gigas behaves oddly and sort of chase the little one (I think the Macracanthus is an adult too, he's 12 cm long).
It crawls over the D. Macranthus and sort of nibble it. The little one is scared and runs away. I didn't expect such behaviour, should I separate them? Could be the Gigas harmful for the Macracanthus?
Thank you.

 

[Marika]

Is your A. gigas male? If it is, maybe it's trying to mate with your D. macracanthus?

 

[Elska]

My A. Gigas is a male. But I thought that my D. Macranthus was a male too! How can I tell?

 

[Marika]

Male millipedes can try to mate with other males, so it's possible that your D. macracanthus is a male too.