Assuming that the basic line is true that the snake escaped from the downstairs store area and made its way up to the upper apartment through the ventilation system, here are a few observations. The type of ventilation system used in this town is likely an oil fired furnace (no natural gas in eastern Canada) which although not relevant, might also have a cooling coil in it for air conditioning. The furnace is likely located in the basement and services the whole building (frankly, if a pet store is in the bottom and an apartment above, there should be two isolated systems for several obvious reasons but the building was very likely built a long time before the pet store was located there). All furnaces have both cold air return as well as the supply side air ducting….and if there was a cold air or supply air ducting grill that was not attached somewhere and a snake got inside the system, it could travel just about anywhere in the ducting except through the furnace itself. It would seem that the cold air return is a much likelier candidate for the snake to have gotten into in order for this to have happened for the following reasons….usually the grill covers are on the side of interior walls as opposed to being on the floor (at least for the first floor) and typically no ducting is used for the air movement…. just the cavity in the wall between the wall studs act as the ducting. Often the grills are installed in a haphazard way with screws that don’t even go into studs… just the drywall. It is thus not uncommon to see return air grills just standing in their location without anything really securing them in place except the friction of the baseboards on both sides. The supply air side will be a rectangular metal duct and obviously for the second storey, it has to travel up through the first floor to the second floor. Once it gets there, 3” or 4” branches take the air to the grills in the individual rooms and those small ducts will obviously be located between the ceiling joists (a larger duct may be used if several rooms are being supplied in which case the ducts that lead to the air supply diffusers will just tap into that bigger duct). For the 3” or 4” ducts, light sheet metal will likely be used as the flexible type didn’t exist when installed based on how old the building looks. As noted, the cold air return is the likelier candidate for a snake to access the system but articles on this have stated that the snake came from above and this might imply it got into the supply air duct…..unless for the second storey, they reversed the conventional direction and supplied the air to floor diffusers and installed the return on the ceiling (there is some logic to having the air travel in this direction and it is not uncommon to do it that way). Regardless, if it was return air between the ceiling joists of the second storey and it came across a poorly installed grill (with screws into drywall), the weight of the snake alone would have easily knocked the grill down…. particularly since this is a flat roofed building, moisture could have gotten in at some point and weakened the drywall or tiles could have been used that support virtually no weight at all. As for a ‘crashing noise’ I disagree and can see how this could have happened almost silently. The grill could have dropped down on to a mattress, drywall and ceiling tiles don’t make much of a noise when it breaks apart (assuming that’s what happened) and a long snake dropping down through the hole on to a mattress and blankets would have been almost silent outside the bedroom.
As for how the snake got out of its cage, that’s another story. Is it known for sure that this is supposedly what happened? Is it possible that the cage itself had an air return or supply located right in it?
I greed.
And even if the the snake did make a large noise in the night, this was a sleepover, children that age can be expected to make a helluva lot of noise throughout the night, playing pranks on one another.
Still I am open to the “killer pedophile” argument if the facts follows it.