If you are trapping from multiple areas, keep some masking tape in your car to mark, clearly, on the trap, where that trapped cat came from so you can return them into the same area. Cats do best when they stay in the same communities. In fact, they may not survive well if you do not return them there.
Trappers are responsible for the care of the trapped cats they catch while in transport even if there is a separate caregiver to receive them for pre and post surgery care. So, what is needed to do this part of the job? First, you must do your best to comfort the cat that you have just trapped. The fastest way to do this is to cover the trap entirely with a sheet or towel while transporting them. If you have a rambunctious cat, isolate them from any others you may have in the same vehicle. I strongly suggest that you put some type of protection under the traps in your vehicle. I use construction grade plastic and pee pads above that. Trust me, you do not want the smell of cat pee in your car!
The second thing you do not want in your vehicle is a loose feral cat. I learned this the hard way. Feral cats do not like being trapped and if given a chance, they will get out of that trap. We use carabiners to insure that ways out of the trap will be stopped. Others might use temporary tie wraps. Take a look at the traps that you will be using to transport the cat and think about Houdini.? Make sure you find a way to stop this from happening by securing the movable parts of the trap. Worst case scenario, if the cat gets out of the trap, and you cannot coax it back inside, just head back to where you trapped it and let it back out in it’s community. This is the humane thing to do if nothing else works.
Thirdly, you need to make sure that the traps are secured in your vehicle. when I have cats in my car, this is easy, but in my extended van, the traps can shift when I put on the brakes. Also, consider that a car accident, although unexpected, can happen. Make sure that the traps are secured where they can not shift around while transporting. If you have a particularly feisty cat, you may also want to use a barrier between that cat and the other cats you are transporting. I use pieces of cardboard to do that. I have had many trapped cats pull on their covers off and get them inside their own traps and then start working on adjacent traps.?♀️ At that point, you will have two rambunctious cats in your vehicle. No fun.
Food or no food?? In order to lure the cat, you have most likely put some type of cat food inside the trap. If you are lucky, they will eat it before you have to transport in a vehicle. If it is dry food, or water, I would highly recommend that you remove it if you are transporting, immediately, to a caregiver area or vet. If it is dry food, the easiest way to do this is to use a stick or dowel to tip the dish/cup over and empty it our while still on the ground. If you do not do this, you will have food rolling around in the your vehicle because once you move, the cat will too, and mostly likely dump it over.