Japanese Bug Fights is a website that showcases videos of different species of bugs in battle, including both insects and arachnids. Users are invited to submit videos. The rules:
1. Two Bugs to a fight
2. Bug fights go on as long as they have to
3. No outside weapons in Bug Fights
Link -via Gorilla Mask
1) Many people argue that the bugs are not sentient, possible (personally It seems obvious TO ME that they are, but I could be wrong, I guess); but if you truly believe that then why on earth would you find it entertaining?
2) Regarding the difference between killing for necessity and for entertainment it just seems obvious that there is a difference (I guess that's why we despise serial killers but not soldiers!).
3) As I mentioned at the start the worst thing about this is not what it does to the insects (sad though that is!), but rather what it does to US, as ilustrated by some of the comments above.