Any idea what these might be? In the shade of a mesquite tree.

[Ptah]

About the size of a fifty-cent piece.

[Ocelot II]

1. Ant lion holes?

https://en.wikipedia.org/wiki/Antlion

[Kali]

14. yes this

ant lions are larvae of a harmless flying insect that is similar to a dragonfly

[MLAA]

2. I think it's mostly lizards though tarantulas do also. I have loads of those holes in the dirt part of our yard.

I’ve never seen a chipmunk type animal around but lots of lizards. I keep meaning to ask the man who takes care of our yard.

I googled and found this:

What digs holes in Tucson?
These creatures dig small, snake-sized holes to escape the Arizona heat–and predators:
Round-tailed squirrels.
Harris' antelope squirrels.
Pocket mice.
Lizards.
Tarantulas.

[surfered]

3. Mesquite beans (seeds)

https://preparednessadvice.com/mesquite-beans-harvest-use/

[surfered]

4. I did not know you meant the holes

[eppur_se_muova]

5. Burrows of ant lions ?

[surfered]

6. Ant lions

It feeds on ants and traps them with this slippery slope. Think Revenge of the Jedi

[umroman]

7. Palo Verde beetles

https://en.wikipedia.org/wiki/Derobrachus_hovorei

[Silent Type]

8. On South Georgia farms, we had holes something like that. They were called Doodlebug holes.

But have never seen them in rocky areas, and they weren’t that big. I wouldn’t camp on top of those or stick my finger in one.

Plus, they kind of look like someone stood there pounding hiking poles into the ground.

[Kali]

15. doodlebugs are the same as antlions

[Silent Type]

18. Thanks. Did not know that.

[Kali]

19. interesting creatures

many of the larvae of dragonfly family are great sci fi monsters.

[CanonRay]

9. Wolf spider?

[Enter stage left]

10. Most likely "pocket gophers ", but could be moles or voles. Very common in Arizona.

Our friends in Scenic AZ call them "rat bastards".

[duncang]

11. If you knock a little dirt in the holes

You will see the ant lion kicking back out the dirt. If you see an ant fall in you can also see the ant lion kick up dirt to make it harder for the ant to escape. Then no more ant.

[royable]

20. If you very quickly scoop up some of the sand from under the center of a fresh hole

and spread it out thinly on a tabletop or the like, then wait a little while, the ant lion will start moving and you can see what it looks like.

[dobleremolque]

12. Ant Lion traps. The ant lion lies in wait at

the bottom of the conical trap. Ants and other insects crawl in and the sloping, grainy sides of the hole make it difficult to escape by climbing up. Ant lion has a meal.

[Ferrets are Cool]

13. This is the correct answer.

[twodogsbarking]

17. You win the prize. Well done.

[twodogsbarking]

16. The Movie "Tremors" comes to mind. Call for Kevin Bacon.