What's this strange behavior?

[Appreciate Creation]

Ok so you have a wild caught chalcodes. It's behavior might differ from one that was kept in captivity.

Wild caught tarantulas might be more defensive but not always.

Two reasons for more substrate. One you already mentioned, in case of a fall. The other one is deeper substrate holds more moisture at deeper levels. The less amount of sub means moisture will evaporate faster.

I've been to the Phoenix area many times since 1996 in all weather seasons. Even though it's a desert environment tarantulas burrow to seek moisture. If they didn't they would not survive long living a life predominantly on the surface. Not just from lack of moisture but also from predators.

The fact you found it by your pool should indicate it was searching for water, possibly.

Aphonopelma chalcodes is a very hardy tarantula and is very forgiving of husbandry mistakes. You do not want to drench it's enclosure so it's like a swamp.

What I do with mine is make a tunnel in the substrate in the corners going straight down with tongs. I use a bottle with a nozzle as it shoots a stream of water which is better for targeting. I shoot water in the corners until the lower layers of sub has a good amount of moisture. The top layer will always dry out faster. The object here is not to overdo it and if the tarantula is seeking out more moisture it will burrow down to it.

That makes sense! Thank you so much for the insight!

 

[Appreciate Creation]

The Arizona blonde's that I've dealt with do the exact same thing.

Interesting! Would you be down to share what their tank setups were like. I'm curious if we can find a correlation between the tank setup and behavior, although Arachnophobephile provided some great ideas on things i can fix with mine.

 

[Ratmosphere]

I keep them on deepish coco fiber, no sand.