Curious on strategies/tips for these guys. Until recently, they were a non-issue as I would destroy them all before they get to my walls. However, every few waves some of them get through and blow up on my wall destroying the turrets, inserters and belts beyond the wall (wall is 2 thick). At first I thought maybe I could just use a blocker wall with a space inbetween, but I still was losing turrets, so I tried a blocker wall with 2 empty spaces and while that is better, I do still sometimes lose a turret, though the higher health turrets seem fine.

I'll be switching my defenses from autogun/flamers to a mix of miniguns, lasers, arc turrets (no damage, slowing), and flamers.

Relevant mods, IR, Krastorio and Rampant. I have a personal tweak mod that reverts Krastorio's laser turret HP nerf and it adds resistances for Rampant damages to player armor, the tank and walls (just so electric and poison doesn't instakill those things).

Use fast explosion dmg delivery defenses: cannon/rocket turrets, capsule launchers - depending on mod. Suicide are less protected against explosion damage. Area damage helps when suicide biters are in mixed swarms, covered by other factions.
2 thick wall is useless against all rampant mobs due to splash damage. Suicide biters bomb a big area - walls can help only with distant layers, but such walls being unprotected will be quickly destroyed by any faction.

mending walls have enough hp to tank a couple explosions and can mend through more if they can repair after a wave, best thin them out with lightning turrets from rampant arsenal / fast shooting turrets (plain laser turrets dont kill fast enough)