Without seeing it, I can't be sure - but here's what I do know;
There is a vent near one of the front corners. It does have metal screen and doesn't allow rodents to gain access. It allows for the escape of whatever hot air isn't drawn into the jets from the Jet Pump Shroud.
There is also a long narrow opening under the door. This should be sealed by the vent screen which was on your spa when it left the factory. The vent screen needs to be cut to fit around any cord or conduit that you use to power the spa, and the opening should be very snugly fit around the conduit or cord so as not to make an opening for critters.
The bottom of the spa is sealed with a hard layer of foam. 60 pound density foam to be exact. If you obvserved a hole in THAT, then you should insist that the dealer come back and reseal it. I have punched holes in the bottom of a spa with the forklift before, it is not tough to re-seal the spa - if you do so before the delivery, that is. Tip the spa up, mix a batch of foam (expensive, which is why it doesn't happen very often in our delivery system...) and brush it over the void. Keep working it for a few minutes until it begins to set. It goes fast, so you have to work quickly. If the spa is still wrapped you can have the crew flip it over and just pour the foam out - it still goes off in minutes. You can also simply but some wire mesh over a hole in the bottom. This is the ticket for once the spa is in place - by emptying the tub, raising it a few inches you can fit the mesh in place and wedge it in.
There are tiny little holes (1/4" or less) which are left in several places on the bottom of the tub as part of the manufacturing process. Those are not a problem.
