Who would win in a fight, all of the lions or all of the ants?

Ants, no question.

Roaches vs. Ants?

It's probably always ants to be honest...
- Probably. There are quite a few.

"Fun" fact: The biomass of all the ants in the world is greater than the biomass of all warm blooded (endothermic) animals combined.

Here's an excellent video where a VFX artist uses CGI tools to visualize what said biomass would look like:

https://www.youtube.com/watch?v=OPoMww9x378

You can go to 6:20 if you don't care about the methodology used to calculate the mass and just wanna see the ant tidal wave moneyshot.
- Absolutely, it's not even remotely a question - the ants would win. Totally and completely.
- That's kinda heccin ant tidal wave
I read a while ago that humans probably have ants out-chonked since some time ago when we started gaining weight as a population.

Had to check back on this since that little factoid has stuck with me since reading it.

Per this journal from 2022, https://www.pnas.org/doi/10.1073/pnas.2201550119

Integrating data from all continents and major biomes, we conservatively estimate 20 × 1015 (20 quadrillion) ants on Earth, with a total biomass of 12 megatons of dry carbon. This exceeds the combined biomass of wild birds and mammals and equals 20% of human biomass.

Because if there's anything worth getting scientific about, it's us vs the ant horde.

Absolutely ants. The sheer volume of every ant in the world working together would be horrifying

That working together part adds so much to the ants' advantage. Even if the ants' entire strategy was "bite lions, no bite ants" they'd absolutely win
- "Bite lion and also any ant not from my colony" would also be a winning move
I just imagine lions covered in ants from tail to nose.
- Your scale is off; imagine an Olympic sized swimming pool filled with ants with a lion in there somewhere.
  
  Now imagine 39,000 of those pools, each with its own lion and ants.
- Looked to see if there was a visual representation of the number of ants in the world and found this
  
  So yeah, would say they'd be covered tail to nose.

Easily ants. Google ant swarm animal. But not right before bed. There's a few insects that are evolved specifically to fight ants but everything else is food to them.

There are an estimated twenty quadrillion (20,000,000,000,000,000) ants in the world. They could wipe out all terrestrial life on earth if they wanted.

Edit: if you see a still image, you may need to click on the gif for it to play.
- Well, that works for most of them but what about fire ants?
Thanks for that nightmare.

Ants easily, there are literally so fucking many. Like there are some singular species of ants that I think could did it alone

What are the lions even gonna do?

“Haha I will bite some of you! And then sit there doing that thing where I make a chewing motion with my tongue out and shake my head vigorously, because it isn’t working!”

Ants all the way man
- I mean they could go underwater and just come up to breathe and eat dead ants

Ants just because of quantity. There's estimates out there and it's just ridiculous amounts of ants.

Humans. Because the lions would be overwhelmed in short order after which the ants would kill each other off.

There are roughly 39,000 lions left in the world, none of which eat insects.

There are roughly 20 quadrillion ants on earth, a significant portion of which will eat live mammals, and almost all of which will kill any ant not from their own colony.

- And then there's the argentinian ants just chilling
a significant portion of which will eat live mammals

O_O

Another vote for ants, although that's partly because I'm a fan of the film Phase IV in which all ant species suddenly start cooperating with each other against humans.