[Opinionated Blowhard]

111,000 spiders thriving in what appears to be the world's biggest spiderweb,

I have to imagine that the only way a colony of 110,000 spiders survives in such close proximity is to cannibalize each other.

[Tallguy]

The colony still must be trapping enough calories to support the colony, a significant percentage of it anyway. Otherwise it would be a biological perpetual motion machine. Can’t violate the laws of Thermodynamics.