Start a dynamic countdown of 12
On a crit success count down 3
On a success with hope, count down 2
On a success with fear count down one.
On a failure with Hope, don't count on anything
On a failure with fear, add one.

After each investigation, roll a D100
1-30 the path is clear and forward
31-35 the path leads up a vertical tunnel for close distance
36-40 the path leads down a vertical tunnel for close distance
41-50 the path leads up a vertical wall with an opening at the edge of very close distance.
51-60, the path leads down a pit and a path opening at the bottom. The pit is very close deep
61-80 The path splits, and the party takes a wrong turn, adding one more to the above countdown.
81-100, the path splits, and the party takes the correct tunnel minus one from the above countdown.

Keep in mind Fall damage for Very close is 1d10+3
and fall damage for close is 1d20+5

Spend a fear to summon 1d6 worker ant swarms.

Spend two fear to summon 2 soldier ants.

When the countdown reaches 6, the party finds the garbage chamber littered with old food and dead ants. This place is quiet and does not seem like it is visited often. The party feels like they can take a rest here if they have the time

Roll an instinct roll to investigate the area.
On a crit success count down 3
You notice that the sand is disturbed, heavily coming in and out of the tunnels. The tunnel walls seem somehow familiar… a thought hits you.. This looks like an insect nest.. an insanely large insect nest.
On a success with hope, count down 2
You notice the sand and dirt going in and out of the tunnel is disturbed as if there is a lot of movement in and out of the mountain.
On a success with fear,
summon 1 worker ants but they do not notice the party
On a failure with Hope,
summon 1d4 worker ants and they immediately see the party
On a failure with fear,
summon 1 Soldier ant and 1d4 worker ants and they immediately see the party.