So here are the descriptions:
Putrescence(tech):
"The specimens indeed are stranded somewhere between life and death, doctor. Prolonged testing shown that they're still decaying, often losing whole bits of their bodies but the process is faster when they have no sustenance. That means that they slowly fall to pieces when they're not eating human brains...
The stench of their remains is terrible, the flesh is actually still infected and we observed a severed hand moving on it's own once. It couldn't actually act logically, but it was twitching for three full days. I'm sure that even organics remains of the infected pose a biological threat. We can't just let them fall to pieces, we have to burn them to ashes.
-doctor F. Austus, company scientiest"
Putrescent Hive(city imp)
"Leutenant Decker ordered for his squad to move forward. The SWAT-s
dispatched single zombies with carefully placed shots from their H&K smg's, running towards their target, the cinema building.
When sargent O'Reily kicked open the door, a multitude of guttural moans welcomed him.
"There are so many of them here they hardly fit inside! The whole place is dead, no survivors here!" Decker shouted into his comm-device.
One of the SWAT team members backed off coughing.
"The stench... The place is full of rotting flesh... God, how awful..."
Decker bravely stepped in front, setting his gun to full auto, his feet sank in somebody's decaying remains.
He could feel his stomach ache as he saw festering dead bodies lying everywhere, some of them still moving...
"Retreat! This place is hopeless! Call for the army!"
Putrescent Hive-the normal description:
When sufficent number of zombies gather in one place they are likely to run out of 'food' and decompose over few days. Such a place will be polluted by their infected remains, posing a danger to every living being.
The stench of such place will act similar to a barricade, making attacking such a place much harder for living beings.Even mechanical entities can be affected by the acid-like fumes and gasses eventually gathering in such a building.
Advisor text:When so much dead bodies start walking a terrible putrescence is sure to sorround them.
(if you find the above description to 'extreme' for just some stench of dead bodies let me know and i'll write something less sci-fi like, won't it be possible to give ****-s an ability to bypass walls?)
Block out the light(tech):
Advisor text:The liiiiight... It hurts, let's smash it!
"So like, dad came early from work that day and said some 'biological disaster' took place and we're in danger. I was about to go to the disco with Brett and said like, bugger off dad, Brett finally asked me out and i won't pass that up, when i saw those creeps moving around our yard.
It was like totally sick, those people were rotting corpses and wanted to eat us! Just crazy, we had to barricade inside our house and i even broke a nail!
Anyway, after the dusk came there was more and more dead folks gathering in our yard, some of them i recognized us our neighbours...
We heard that old Mr. Prescott yelling from his house across the street,
"Keep the light on! They're afraid of light!"
You see, we had this cute decorative lights in our brand new fountain, there was also a big lamp in the yard that could be turned on from inside.
When we turned them up those creeps backed off and started to cover their eyes. We thought we were saved but one of them punched the lamp and smashed it to pieces. He started burning from the electricity, yuck...
Then the whole stinking crowd started shambling towards us..."
Smash the lights(city imp)
"Mickey driven his SUV trough the empty street, it was dark and all of the streetlamps, neon and lighted signs on shops were destroyed.
What a riot, he thought to himself. He knew the creatures didn't like light, but how they got smart enough to destroy it?
Around the corner he saw a zombie twitching on a partly destroyed "Fat burger" neon sign. It got stuck in the wires and was slowly dying from the electricity while the neon blinking from all the damage.
Suddenly the neon stopped working and the creature was free, it then turned in his direction...
Smash the light-normal text:
When the zombies by pure chance figure out how to destroy lights they fell much more at home in the city while humans will be easy prey in the darkness...
Maybe 
