Also found some spore bats at (64,54)(52,65)(54,55)

Around the lagoon north west on water ledge are more than enough spore bats and fen striders are all over i got all the quest items in 5 kills of each thing very easy!

Around the Lagoon, I had a 50% or higher drop rate, and the mob are plentiful.

i found that a good spawn point is
(53, 59) LOTS of them

good luck

Yeah, the above comments are reasonably accurate.

Managed to get all 4 tentacles in a row, but u HAVE to be near the lagoon to have even a slight chance of them dropping.

Looking for spore bat eyes now, im assuming they'll act fairly similarly

I found the Fen Striders hard to find; and when you found them, their drop rate was terrible.
I think I must have wiped 40-50 for the 4 tenacles.
So to save you the pain I went through, here are the co-ords for my tenacles

56.53
61.50
64.59
67.72

Hope this helps

The Fen Striders had a decent drop rate - took 15 or so kills to get the tentacles.  The Spore Bats, however, were a completely different story.  I started out needing 50,000 xp to level, and at about 1000 xp per Spore bat kill I had the 4 eyes one kill after I leveled, which means I killed about 50 Spore Bats (NOT younger or greater) to get the 4 eyes.  Worst drop rate I've ever seen. 

I found the spore bats were harder to find and had a very crap drop rate...the fen strippers are everywhere and wernt a problem.

According to my add-on, drop rates were as follows for me:
Spore Bat Eye 23%
Fen Strider Tentacle 50%

I roamed the West side of The Lagoon.

At first I tried killing spore bats, I may have killed about 15-20, "NO DROPS".  Then i just started killing the fen striders near by and had drops from every kill.  After i was done collecting fen strider tentacles, i went back to the spore bats, and per each kill there was a spore bat eye dropped.  So maybe if you try killing the fen striders first and collect their tentacles, then when you are done with that, move on to the spore bats.  If you run out things to kill, go look for the stingers near by to collect Diaphanous wings that drop after you kill then (drop rate not so good).  Below I will give the quest name and coords.

Gathering The Reagents - 63, 58 - There you will find the Fen Striders and Spore Bats.  Remember to try out killing the Fen Striders first if you're having trouble getting drops from Spore Bats.

if you run out of things to kill for "Gathering The Reagents" quest, then do the "Diaphanous Wings" quest which is very near by, coordinates are:

Diaphanous Wings - 67,61


Aquilles
Terenas Server

drop rate SUCKS
gg blizz -.-

Its around The Lagune. Do not kill the Young spore bats, they ont drop anything for u.

Take the naga quests while your around the lagune, it will save you much time.

Do the quest in the morning, cuz its a bad drop-rate. Then the drop-rate is better, cuz ppl have'nt been farming them.

63,57. Around that area.

Drop rates are HORRIBLE! Mind you why doesn't that suprize me. All drop rates in WoW are horrible. Sucks the fun out of the game! gg Blizzard.

Took 10 kills to receive 1 from spores.

I just finished this quest earlier today. The fen strider tentacles dropped really easy for me. I only had to kill about 5 to get them all. The spore bat eyes weren't as easily dropped but they weren't as bad as i was expecting, from the sounds of these other people. I circled around the lagoon once and killed just the spore bats (not greater/younger) and was able to get them fairly quickly.

The bats eyes Have an Awesome drop rate but....

im not too sure about the fen striders i think if u stick to bats hen hit the fens u'll finish relly quick :) hope this helps and yes ther r tons by the lagoon.....

I found it to be rather easy. I got my bat eyes after killing about 20 or so Spore Bats. On the other hand, the Fen Striders weren't giving out. I had to kill 30 or so for them. On my Druid I got "lucky" and within the first couple of Striders and Bats, I got all of the Reagents.

I killed about 12 sporebats surrounding the lagoon until an eye finally dropped. Very bad drop rate on them. The tentacles, on the other hand, were about a 50 percent drop rate. Very pleasant. Basically to do this quest, just go to the lagoon and grind.

took me no more then 10 minutes to get everything

Fen Striders around 64,51 - 64,58 more or less decent drop rate, spore bats drop rate is damn low ... real grinding opportunity hehe

Their are alot of great spore bat's near 20.18.Drop rates are bad, but you will gain xp so who cares :)

i killed one just a minute ago and it dropped one! drop rate is terrible but they do drop it!

DROP DROP DROP

every1 higher then is right the drop rate is TERRIBLE!

This quest took a ridiculously long time. After over a half hour of AoE Tanking 3 Spore Bats at a time and not receiving a single spore bat eye I decided to open a trouble ticket with a GM. After that 10 minutes later 4 dropped out of the next 6. I dunno why to say the least I was a little pissed.

The fen striders were another story, it seemed 1 out of 3 dropped em so all in all around 12 striders to get them all.

  LOOK NEAR THE LAGOON FOR SPORE BATS :D

I remember doing this quest on my main but i never new it would take this freeking long. I have ganged 4 bars from doing it and i still have 0 of both (im 63) and it just sucks completely plus this quest isnt as worth it until u can morph into that dude. :)

Actually i don't mind having to grind a while to get the stuff at least u can turn into an arakkoa and get money

While doing this quest, I had a thought, maybe there is only ONE spore bat with an eye and Bliz forgot to add the rare dragon to his name...
Maybe all the other spore bats hold him in awe (cause of his eye), maybe he's a mutant bat, kinda like the X-men...
that's it!
be on the look out for a spore bat with metal spikes coming out of its hands and a bad attitude.
Logan-bat!