It's a War crime tunnels were not used for sheltering children those deep enough that the IDF could not reach without a Total reoccupation . Also Blant Child Sacrifice.

Before we became humans we were small rodents living in the roots of trees in tunnels which we dug with our teeth and feet. Are we going to become rats or gophers again when life above ground becomes extinct? Or, do we stop fighting?

Train rats to seeks and follow specific smells (for instance, rocket launchers). Infuse them with low dosage of radioactive elements (PETA won't protest, since rats do tolerate radiation). Free them in Gaza, and start reading radiation sources from above.

can they be gassed ?

There is a simple way to locate hidden cavities and destroy them: injecting flammable gas, that would trigger the mines, booby traps and ammunition stockrooms.

how many there are in other areas like Golan and the Northern border/West bank.