NO, don't do one at a time. If possible, have enough traps to try and trap all at the same time. If you have 4 cats, setup 4 traps. Once one goes in cover and remove immediately! You might check with feed stores, rental places, Humane Society, etc. and see if they rent traps out.
Here's a link to the group we work with, which might give you more information:
www.azcats.org
(we're listed on the home page for getting an award from the City for TNRing, and for Cat Fancy Magazine doing an article on us).
Trap-Neuter-Return (TNR) is a full management plan in which stray and feral cats already living outdoors in cities, towns, and rural areas are humanely trapped, then evaluated, vaccinated, and sterilized by veterinarians. Kittens and tame cats are adopted into good homes. Healthy adult cats too wild to be adopted are returned to their familiar habitat under the lifelong care of volunteers
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