I live in Houston and store my bikes at ambient temperature in a garage. I have not experienced anything like what you described.

It is not real clear from your post if the holes you find are only on the inner tubes or both the tube and the tire.

Thoughts:

1. With a long time between rides, it’s probably necessary to pump them up before each ride. I’m adding air every 2-4 weeks. Low tire pressure can give pinch flats somewhat like your description.

2. If the tires are old, they may have developed flaws that could rub holes in the inner tube. If this is the cause you would expect your patches to be in about the same place or the equivalent if the tube was flipped on re-installation.

So there may be chupacabras in the area but no indication they target bike tires or tubes.