Question about trapping

So I'm new to TNR and just bought a havahart trap. I know they are not supposed to eat after midnight, but the clinic doesn't open until 8AM. My question is, if I catch a cat between 10 PM and midnight, am I just supposed to leave it in the trap all night? Will they be okay in there for 8-10 hours? I have no place to keep them inside, aside from the tub. But I don't want to risk bringing in fleas or stress out my own cats.

A small amount of food is just fine.  I have trapped first thing in the morning and the cat has had a bit of food then. 

If you trap the cat at night, make sure you keep them in a safe environment such as a garage, basement or the bathroom.  Keep the trap covered with a towel, blanket or sheet.  DO NOT let the cat out of the trap.  You do not want to leave the cat outside in the trap overnight.  I always use my garage or basement.  I just place an old tarp down on the floor and set the covered trap on top.

If you have a shed, that will work, too. Anyplace that will keep the cat out of the elements and protect it from nosy night critters, like other cats or raccoons.

Trapping is scary and nerve-racking, so take your time and try to relax. Always remember that what you are doing for this cat is greatly improving its life. He may not appreciate it but you are the best!

Unfortunately I do not have a shed or basement. I live in an apartment with a parking lot out back. They hang out near my car so I'd be trapping there. Since it's not a good idea to leave them outside overnight, I will try to trap one around 5 or 6 AM. So it's okay if they have maybe a teaspoon of tuna a few hours before surgery?

That will work. Let the vet know she ate something. He'll probably spay her later to give her some time to digest it. Only put out a small amount - a teaspoon or less is good.

Good luck!

Where do you plan to keep the cat after the spay/neuter?  You will need to keep them in the trap overnight for a male and for 48 hours for a female?  They need a temperature controlled environment so you will need to keep them in your bathroom.  Maybe your vet will keep them overnight, but most spay/neuter clinics have you drop them off in the morning and pick up in the late afternoon.  Just something to think about.

Good news. The clinic said I can bring them in the afternoon before surgery and they will keep them overnight, no charge. After surgery they can keep them an extra night or two for $5 per night. Thanks all.

That is fabulous - what a great deal. Thanks for the update.