In Maine, I have seen them wet inside but don't recall any with bugs inside. The tops is frequently folded over and there are usually some in the fold but not in the bag.

[big spider]

Where's the "yuck" button?

As others have said some pouches are found in better shape than others. I think it depends on the type of bag and tape that is used.....some planters are more meticulous than others in making their pouches as well!

Yowsers! Is that picture of the spider for real?

Yep, that is a Woodsman Spider.

DZ

Actually, after some searching it appears it might be (more specifically) a Olios giganteus (Giant Crab Spider):

https://spiderid.com/spider/sparassidae/olios/giganteus/

If I’m understanding this website, it looks like sighting one is a rare event:

There have been 37 confirmed sightings of Olios giganteus (Giant Crab Spider), with the most recent sighting submitted on June 18, 2018 by Spider ID member jennylee.

I have returned to letterboxing a lot recently after some years of being semi-inactive. During that time pouches have apparently become more common in my local area in Michigan. I saw them rarely or never in the old days, but have recently found more of them than boxes. So far my impression is not good. The ones hung inside shrubs have been all right (except when they've fallen, which seems to happen not uncommonly). The ones I've found on the ground, either because they fell or by design, have almost all been wet or buggy. One I found recently had been colonized by ants under the flap who grabbed their eggs in a panic and rushed out willy nilly as soon as I opened it up. I actually felt bad for them having their colony disturbed. The pouch itself had a inch or so of water in the bottom and while the logbook was fine, a hitchhiker that had been left there had its log destroyed. I have to say I have not gotten a great early impression of pouches. Others' experiences no doubt vary.
-PR.

I think it depends on the type of bag and tape that is used.

My experience with pouches (primarily SW Ohio, Central IN) is that the placement makes a difference, more than the materials. Learned the hard way about bugs in the fold. Very memorable....

In my area, at least, pouches seem more subject to weather than a good lock and lock, other factors being the same.

There is a variety of large spider that seems to like to nest inside the box tho I’m not sure how it gets in. Smacking the side of the bird house a few times with a stick recommended.

[big spider]

It doesn't need to be small, it just needs to be smaller than your shoe.

...there are usually some in the fold but not in the bag.

I think that's the concern being discussed. There might not be bugs inside the bag very often, but they are nearly always in the fold -- and that's bad enough, because you have to open up the fold in the course of opening the bag.