Zerg strategy against Void Rays in SC2

Playing a lot of 3v3 lately and have been strictly Terran up until lately, swapping over to Zerg.

Zerg has been going great - I think it's a race that can only be as good as your ability to macro, which isn't a problem for me now that I've played for a while; problem I'm having with them is they seem to have nothing that will counter a reasonable fleet Void Rays.

Terran was fine if you had enough Marines, Vikings or Yamato power, Protoss is fine if you have pretty much any unit that can hit air that's not heavy (ie Carriers).

Hydralisks get wasted, you can't just hope to overpower them before they defeat you with Ultralisks because VRs slay them, can't use Neural Parasite because there're too many of them, Corruptors are plain useless, Mutas are too weak and have too little range which means you lose 20% of them just to get in range.

Am I missing something? A strategy along the lines of killing them before they get VRs or restricting their gas/teching isn't really viable in 3v3 unless your entire team is aggressive from the beginning - in which case you normally win anyway. This is a question for mid-late game.

Any suggestions would be awesome!

So, I'm going to assume you're talking about late game Void Rays instead of an early game VR Rush in PvZ.

Late game Void rays are tough, no question about it, however there are a number of strategies which provide effective counters.

Pound for pound Corruptors actually beat Void rays, however, the large mass of VR usually mean they have time to charge, at which point the tides will turn against you. Hydralisks fair much better (as they're not armored and don't give VR time to charge), however, they frequently run into positioning problems. Since VR can stack and Hydra have slow movespeed, you often see Hydralisks out of range and unable to attack while their closer brethren bite it. You can use Burrow to help here, but that's not always an option.

For late game Void rays (or really mass anything) there is always one place I go: Infestors' Fungal Growth. Now, sure VR have a nice 250 combined health+shields, and Infestors only do 36 Damage per 4 seconds (46.8 vs armored, which VR are), but anytime you see Mass anything, you should be thinking of that nice damage multiplier you get for hitting units close together... didn't I mention VR stack?

Frequently I'll engage a VR group with Hydra/Corruptor and as they start to stack I'll throw down the Fungal Growth. The added DPS is more than enough to turn the tides in my favor. What's more, if they catch me out of position, a Fungal Growth or two will lock them down while my Army gets ready. Remember Fungal is Range 9 and VR have range 6. In theory you can even Fungal them to death (if he stacks too tight).

Now, I'm not saying Infestors are THE counter to Void rays, or even the best counter, but when I see a fleet of stacking units... they are the first thing I think of...

Bonus:

A lot of players struggle with early game Void rays. I think this is a reasonable opening for PvZ. To counter this, I usually drop a second Queen (if I scout it) or bring my Queens together to force them off (this is why spreading that creep between your nat and main is so important early on). I also regularly get an Evo chamber. I think it's worth it for early upgrades and +1 timings, and it's cheep (75min) incase I have to deal with Banshee/VR harassment.

Even if you can't kill the guy going mass void ray, you should know what he's doing. If you don't know what he's doing, and you haven't heard from him long enough for him to amass an army of, say, 12 void rays, then scouting is by far the biggest problem.

So once you know he's massing void rays, just start building the counter between you and your teammates. I believe equal cost of corruptors or hydras will beat void rays, as long as the void rays don't get charged up.

Try to keep the void rays uncharged. If they get charged against your army, run away and let the charge wear off. If they're charged in your base, the base may be dead, so decide accordingly what to do (retreat to ally base, rebuild, counter-attack....)