Camponotus workers decapitated?

[MooseBeard]

A couple days ago I checked on my Camponotus(Herculeanus I believe) and I saw there were a couple black things in their setup. Upon closer inspection I found that they were the heads of a couple workers, one being the head of one my first ever majors. What could have caused this? There doesn't seem to be any other remains of the decapitated ants, just a couple heads and a leg here and there. Did they cannibalize? If so, what are some causes to ant cannibalization so I can try better to avoid this happening again?

[AntsLuxembourg]

are you feeding them properly? this seem to be a case of not enough food so they start to eat each other out of hunger. So you should offer them some proteins by feeding them insects and also give them some honey for the needed sugars. At least offer some honey first. I am sure they are going straight for it.