How do headcrabs/zombies see?

[Protricity]

I'm working on a short spin off movie script and I'm wondering if anyone has any suggestions as to how head crabs and zombies detect and locate enemies.

Sound? Extrasensory? Small beady eyes we can't see? They seem to have good aim with large gas cylinders.

Thanks

 

[z0mbin3]

Most likely they have optic clusters in the wrinkles at the fornt of the headcrab.

 

[Narvi]

Could be anything. Sonar. Electrical sensing like sharks. They aren't hampered by complete darkness, so it's probably not a light-based sensory mechanism.

 

[Druckles]

Apparently they do have eyes, and they're more visible in the Half-Life 1 skin of the headcrabs. Zombies will inevitably see by the same method that the headcrabs use.

 

[ríomhaire]

My vote goes to echolocation, like a bat. It would explain why they never stop making noise.

 

[Eejit]

They could indeed have light detection without having recogniseable eyes, but their sight would be poor.

I vote electrical sensing like platypi.

 

[yakuruto]

It's a very complex set of different organs that allows them to see (very blurry, in black and white) and to read heat signatures. Also, they have adapted quickly to Earth's environment and developed a carbon dioxide sensor to track potential preys.

 

[Emporius]

My vote goes to echolocation, like a bat. It would explain why they never stop making noise.

I would think that they would use a higher wavelength.

I vote electrical sensing like platypi.

Except that wouldn't really work in air

 

[ríomhaire]

I would think that they would use a higher wavelength.

Maybe they emit noise in a higher wavelenght aswell.

 

[Naph]

The massive cheekbone like crevices on either side of the head crab act as reverse loud speakers. Imo.

 

[FrostXian]

Raising The Bar mentions only Gonarch, not having any eyes. This would probably mean the headcrabs have a pair.
If it'll help, Gonarch is meant to be able to sense vibrations.