(CW: images of an assassin bug feeding on another assassin bug.)
Assassin bugs are known to feed on other insects. Here's one spotted feeding on another assassin bug. A Campsolomus sp. feeding on a Cosmolestes picticeps spotted at Tampines Eco Green on 14 April 2023. Yes, they are two different species, so this is not cannibalism.
On iNaturalist [ https://www.inaturalist.org/observations/154811474 ]
@sohkamyung
Assassin bug is an assassin bug to other assassin bugs
@oliparch @sohkamyung beat me too it! "It's assassin bugs all the way down!"