3 questions

[Mocht]

(1) Are rods of pesticide useful
Whenever I use them they kill lots but not enough, and the next round there are just as many as before

(2) Are devices that emit beams of light only good for killing orcs

(3) Is there a reason that the always small levels option doesn't effect many dungeons

[GenericPseudonym]

(1) Are rods of pesticide useful
Whenever I use them they kill lots but not enough, and the next round there are just as many as before

They're useful to sell in town for about 1000 gold. The easiest way to deal with a lice infestation is to just walk away and take a staircase instead of carrying around a device specifically for it, and the rods only do about 5 damage per zap so they're too weak to kill anything more durable than lice, even yeeks or kobolds.

(2) Are devices that emit beams of light only good for killing orcs

There are two different kinds of light. Weak light, from wands of light or staves of starlight, will only damage light-vulnerable monsters like orcs or vampires.
Strong light, from rods of beam of light, staves of starburst, high-level angels' starburst spell, ethereal drake or light hound breath, etc, can damage anything (and resistance to it is pretty rare)

(3) Is there a reason that the always small levels option doesn't effect many dungeons

I couldn't tell you the answer to this one, though.

[murphy]

(1) I havent found any use for rods of pesticide, I never bother to pick them up.

(2) in addition to orcs, wand of light is effective against sand dwellers, and they drop lots of items. wands of light are also good for illuminating a corridor which can be tactically useful sometimes if you have a ranged attack. I usually find it worth carrying one wand of light, and then swap it for a rod of light when I find one of those. might even carry two. as Generic Pseudonym pointed out, rod of light does good damage to just about anything

(3) no idea

[HugoVirtuoso]

(3) That's probably by design. Some dungeons are designed to be large spaced like the Lonely Mountain