How do they know if it’s day or night on the island if they spend all of their time sleeping in caves?

Pet it

I've seen them in the central cave on the island.

During the day, they are very sluggish and attack slow. At night they are a frightening sight with much higher speed and attack. Beware when encountering them at night.

Can be found in Carno island cave, south west lava cave, south east cave near Stonehenge, Central cave near volcano, and possibly others. They are very rare spawns but if checked regularly you can encounter them if looking to tame.

I found mine sleeping in the jungle near vikings bay on the ragnarok map.

Encounter at night? RUN

These are no joke a level 15 killed my 240 wolf in well under a minute, use extreme caution when around them

Found my mega near Viking bay on rag people need to see this so ^vote

Only found one on ragnarok lvl 50 by the ribcage cave at viking bay

They will knock you off your mount if you look at them too closely. (They're very self-conscious.)

Damages wood structures. App is wrong. Use a stone taming pen.

Run when you see it at night a lvl 20 killed my 197 argy within a min

These guys are a pain in the butt do not go in caves unless you really prepared

!!WARNING!!
Exists on the map of aberration specifically to fuck the brains out of your ravagers.

Found them more commonly in the Carno Cave (Artifact of the Devourer) instead of the Chitin Cave

On the island, check the artifact caves.

I have seen them spawn on top of snowy mountains in procedural arks, however.

Just found a 145 in Easy cave on my 160 Raptor...

On Aberration they don’t sleep during daytime so they always have the nighttime buff. On the plus side it means if you tame them they are always at their strongest. By far the best attack mount on the new map.

During the night don't go outside.......you will see glowing eyes and think it's a troodon which is scary enough so you get on your take and then you find out it's not a troodon.....stay inside at night this thing was spawned by fear and death itself and just pray you do not encounter this thing it will kill you...