Board Thread:General Discussion/@comment-31122347-20170218033440/@comment-28365753-20170222231019

There are probably rivalries and the like, but having demonic silver weapons makes for little killing. If you are asking if they eat each other the answer is no. However there are regular animals in the MGE so I can totally see an Arachne eating regular moths. The more martial ones like salamanders and hinezumi definitely fight but not to the death.

As far as other rivalries the only ones that are mentioned are dark elf v. elf and dwarves v. elf. The prey mamono might feel uneasy in the presence of predator mamono but that would be more residual thoughts than anything else.