Although the dragons have long since fled, one can still run across a beast or two... especially late at night in the wrong place. The most ferocious of our land beasts are listed below... Sharpen those swords!
Cockroaches are often considered hideous and take some getting used to. I bet you find it hard to believe that any amount of getting used to them will make them less horrid. I do remember my first encounter with our island cockroaches during one of those nights when they fly around. Yuck! Truthfully, though, they don't usually go crazy like that, they're usually quite shy hiding somewhere until after all the lights are off. Unless you turn the lights on late at night you'll likely never see them. I believe the flying has some mating significance and is certainly not everyday behavior.
Thankfully our roaches are not known to be particularly dangerous, nor for spreading disease, nor do they bite. They just fly around sometimes, horrifying locals and guests! Still they are gross and it is not hard to feel sympathy with your reaction. Cockroaches should be associated with the tropics, not with any particular Inn as they are pretty much everywhere and will be found in virtually all rooms and buildings in Hawaii... after dark anyway. I have seen building which have not been cared for and the roaches can be insane. My point is that they are everywhere and B&B owners hate it hearing complaints about these guys. I assume that all Inns are spraying and cleaning as best they can. A note however is that these insects are the primary and necessary composting machines for dead tropical foliage; while gross we all enjoy Hawaii more with them than without them, even if you don't realize it.
Roaches eat dead organic stuff and appear to prefer human food for some reason. It is frustrating when we hear about guests getting freaked out about roaches, so generally Bed and Breakfasts do all they can to keep such experiences to a minimum. Even so, we still apologize to all guests for the occasional roaches that do foil all of our defenses to get into your room.
Sadly there is another villain in the cockroach story. When you stay in a room, maybe come back from a day exploring, and nearly everyone brings in bags of edibles from the car. Half a bag of chips, a soda can with sweet smelling drips, a carry out food tray... This happens at least every other night for most rentals. Just how much poison is required to kill cockroaches who get fed every night?
On the other hand are visitors really expected to NOT bring food into the rooms? People who live here have tight places to keep the food, a refrigerator or cupboard with sealed containers. We clean up the kitchen before bed. But what about visitors? Even when they clean up the room, the food waste goes in the garbage bin inside the room.
So what can you do? While your experience of roaches in your room has more to do with the previous guests than with whatever you can do, this does not mean do nothing. Just knowing roach reality should be helpful, knowing that they will just be around, unless the owner just sprayed yesterday, should also help a little. Panic or upset are likely the worst you can do. So here is my advice: clean up well and keep your food in the car. Pack or find a sponge and wipe down the tables BEFORE bed. A plastic bag will not protect you much, they'll gnaw right through; your suitcase may be OK if you close it up. Finally, if the beefy vegetarians are simply intolerable, pack your own can of bug spray and hit the floor boards all around the room. Of course then it smells so plan a few hours ahead so the fumes can get out the windows.
Mosquitoes: This advice will pertain to all hotel rooms in the tropics; the mosquitoes in your room should not be viewed as an indication of hotel cleanliness. On the other hand if your inn is in a wet green location and there are no mosquitoes in the evening then someone was almost certainly busy with the bug spray just recently.
Sadly I am well aware of how a single mosquito can turn an otherwise pleasant night into misery. It doesn't help much to remind myself that the noisome little insect will not really inflect significant damage to my person. I have often wished that they would take twice as much if they would just be quiet about it!
Available, at nearly every store, are these green coils of 'incense' that contains pyrethrum and other chemicals which aren't so bad if the windows are open... though often horrendous if you can't get fresh air into the mix. This is my remedial course of action for dealing with mosquitoes in tropical hotel rooms: Carry some of the insect incense and light one as soon as you get in the room, close the windows and leave for ten minutes. When you come back open the door which allows a stream of fresh air in. The little buzzers follow that fresh air right out of the room in a couple of minutes. Close the door. Put out the coil. Open the windows. Turn on the fan and chill.
Alternatively, turn off the fan, turn on the lights and just hunt the bugger down. Swat! There's probably only one anyway. Just lying there and stewing doesn't work though maybe with lots of practice you can learn to ignore them. Lucky for me things haven't gotten that far yet.
While this is not exactly scientific data, it seems to me that those folks who live here don't have that same itchy swollen and red reaction to bites. Probably some sort of immunity thing going on. Anyway locals may forget that a mosquito bite can be really annoying if you are having one of those terrible reactions. This will explain why local folks don't acknowledge mosquito bites in a satisfying way. The buzzing however... I have not heard of any immunity to that.
We can't actually lay any claim to these reptiles, though Hawaii may well be the only place you meet them, they are found all over the tropics in general. As a local I have learned to love these critters and their chirp-ping at night. It is easy to imagine them eating a whole bunch of bugs which they do indeed do. They are very unlikely to get into your food, nor to bite or carry disease. Certainly they won't be interested in getting close to you.
For reasons that seem strange living with them all these years, some people think they are creepy. While in general people around here do not appreciate mosquitoes or cockroaches we all seem to love our geckos. So try and relax around them as they really pose no threat to you, they are not going to eat your food even... (ok, I assume that you don't compete with geckos over flys and so on).
Centipedes: Should you be so unlucky to encounter one of these pre-historic leftovers I feel sympathy for your reaction. I have to warn you that they come in several denominations, the most common is dark brown and up to 6 inches long... looks deadly horrifying. Unless you are a child or have compromised health, these will likely not be any more painful than a bee sting... nothing like what one might expect from appearances. The other one is not so abundant but is no more than half the size of the big ones, they are much lighter and usually have some blue on them. I have gotten nipped by one of these too and I'd go for the big one every time. You probably won't see one of these but squash away as far as I am concerned. The big ones do not deserve the horrified reaction they get from almost everyone, yet you could easily see one of these. After you freak-out when you see one, perhaps you can calm yourself down by remembering that they have no interest in you. If they pinch you, it will swell get warm and hurt... but honestly it is still in the bee-sting category. The little blue buggers though, still not hospital bad but ouch the burn!
Other Beasties No, I did not cover all the critters. On land there is still the scorpion - there are several of these too but rare even in the dry side which they prefer. As long as you don't stick your hand under boards and stones the chances are slim you will get to see one. There are snakes, but even if you encounter one you will probably mis-identify it as a worm which it resembles in many ways. There may be a few more which I have not mentioned, but if I can't remember them then you probably won't encounter one ;)
Of course there is the ocean, which you will probably go in no matter what I say, a hotbed of painful experiences. Dangers there are extensive including such horrors as rocks and coral (you laugh, but scrape you leg on one and then chuckle!), rip-tides, weird sets of huge waves that come out of nowhere (almost lost the whole family to one of these once), Jelly fish - nearly never, and of course: Sharks. My personal favorite is a lack of air.
It is odd that the most likely danger is the one which should be most obvious. Our lungs do not work well under water, and if you are having any fun at all then you'll likely find yourself farther away from the air, at least once, then you really prefer. I'm just pointing out the most likely way to die from Hawaiian ocean is drowning. But you knew that already, right?... Right?