POISONING Poisoning them, of course, is out.  It takes too long and you can't control where they finally die.  You could also take the animal to a vet and let him take care of the job. Make sure you check with the vet beforehand, to see if he takes care of wild animals, that he will do this and what the cost will be.  You could also check with local animal shelters, to see if any of them will do this.  (Usually, they won't.) SHOOTING Shooting them might be against your own local laws, for discharging firearms, or even as game animals.  Besides, it injects a bit of danger, when you're dealing with firearms or ammunition.  Even shooting them when they are actually trapped is not such a good idea, many have asked about that.  Most traps are made from galvanized steel, meaning a mis-aimed bullet (or pellet) could ricochet and perhaps cause a problem.  And, as for the ‘cruel' part, what if you aren't successful on the first try...? However, those that are experienced in the use of firearms, and using the proper firearms, used in a professional manner, could certainly be a viable alternative. GLUEBOARDS That's just what it says.  A board with a pressure-sensitive glue.  The idea, of course, is that the animal will step on it, become entangled even more when he attempts to get off the board.  Finally becoming completely entrapped.  At which point, you must either await his death, sometimes a long drawn-out affair, or dispatch him before he dies on his own.  Does that sound gruesome or what?   And that's assuming he actually becomes entrapped.  What if (and this happens quite often) he only gets partially trapped on your glueboard?  Most of the time, they'll be able to chew their own leg off to get free.  I call that pretty macabre. SNAP TRAPS You gotta have a heavy duty snap trap to kill a healthy, adult squirrel.  A rat-sized trap at the very least, no mouse traps.  And I should tell you right now, squirrels (and rats) are a lot smarter than mice, so they don't fall for the snap-trap thing too easily, and if you miss him the first time, you'll probably not get another chance too quickly or easily. Not only that, but if his friends see him dead (or hurt) in your trap, it might affect your future catch.   I have experienced some pretty gruesome scenes where squirrels have been caught in traps, enough so that this would not be a recommendable method unless needed under special circumstances.  There's also the same problem as with the glueboards - partially caught squirrels will chew off a leg to get free.   FREEZING What about freezing?  I've been asked about that.  Well, yeah, it would work....  But it's a pretty slow gruesome death if you ask me.  Besides, I don't think I want to put a squirrel in MY freezer, even if it would fit, I don't know about you. GASSING Like what kind of gas?  Just about the only kind that a layperson has access to is carbon monoxide, as in car exhaust.  You should be very careful using this method also. I have a friend, another exterminator, that tells the story of his neighbor, who almost killed his wife and two baby girls doing it this way.  Besides, it takes awhile, and I would certainly call that on the cruel side.   A customer of ours uses a large trash bag, in which he places the trap.  He then uses an old vacuum cleaner hose from the exhaust of his car, inserting the other end into the trash bag.  You will need to also make a hole in the bag to relieve the pressure and keep the bag from splitting at the seams.  Carbon monoxide is dangerous to you, so if you use this method, make sure you do this out in the open where it is well ventilated. Another consideration is the back pressure to the exhaust system.  Our mechanic discourages this method for that reason, and the safety issue. I guess you could use one of the noble gases, maybe krypton, argon, xenon or one of those.  Since they are heavier than air, you would need an appropriate container for your squirrel, deep enough to contain the gas and the squirrel in its cage.  The gas displaces all the oxygen and death ensues.  Actually, that would be the same as drowning, and would take approximately the same amount of time.  Except for the stress of the animal being slowly aphyxiated, the gas is painless.  Hope you have deep pockets, this method will not be cheap. Or perhaps carbon dioxide, which might be a whole lot cheaper to obtain.  Again, depending on the concentration, this could be quicker or slower.  And if you're thinking maybe just put him into an air-tight box and just let him use up all the air....  Well, I think that would be pretty cruel. Exterminators might use cyanide gas, which is pretty quick, it's the same gas used for capital punishment, in gas chambers.  But that isn't a safe and viable option for anybody that isn't a licensed exterminator.   Sometimes a hyperbaric chamber is used.  This is a chamber where the air is removed. The animals suffocate - that's plural because most of the time they put in several animals.  And it takes awhile too.  Besides, there's a lot of pain (as the air is evacuated) before the end. DROWNING Drowning a squirrel generally takes about a minute or two.  You secure the trap doors, so the doors will stay closed, and then dunk the entire trap, squirrel and all, into an appropriate container, filled with water.   ASPHYXIATION This is probably the quickest, except for (maybe) shooting.  This can be done by hand, from a handling cone, or mechanically, by a squeezing device.  Someone with experience, doing it by hand, can do it within a couple of seconds.  You squeeze the animal, the heart stops almost instantly.  This method is not for the faint of heart. COOL IT You also have to remember that every place has their own set of rules and regulations about this.  Make sure that you comply.  For the most part, in most locales, the rogue squirrels you catch, on your property, the ones that are disrupting or destroying your property, are yours to deal with as you please.   Unfortunately, official enforcement is often a personal thing, with some officials advocating methods or procedures that are not entirely legal even according to their own rules.  It's sometimes personal enough so that it depends on who you ask - and when - and in front of whom.... REMEMBER THIS: Many people are acutely sensitive about matters such as this, so whatever method is used, it's best to do it out of the public eye.  There are people out there who can make it difficult for you, even if what you're doing is entirely legal.  They will have no understanding of your squirrel problem, and will not be able to see, or even care about your point of view.  It is best not to have to argue your case, you will have a difficult time changing their minds.