After a while, they learn that the lights are just lights. However, if they occasionally get a human yelling and throwing rocks at them, when the light goes on, they stay wary.

Here's some coyote info to pass on.

*DO NOT TOSS FOOD TO THEM! DO NOT LEAVE FOOD FOR THEM! If they lose their caution around people, they go from ghosts to aggressive panhandlers. Then it's animal control and traps and guns and dead coyotes ... and maybe rabies shots and expensive trips to the ER or the vet. Keep them wild and wary.

1 - Do NOT leave coyote food outside. There's plenty of natural food for them, such as entire golf courses full of fat bunnies, but if they know there is always food in a certain location, they'll be more likely to stick around longer.

Garbage -- Keep a secure lid on all your garbage, and don't litter.

Compost -- Keep compost covered and reduce food odors by adding newspaper shreds or dried leaves. Don't put meat in your compost.

Pet food -- Do not feed pets outside or store their food outside.

Fruits and vegetables -- Coyotes will eat fruit so pick your fruit before it falls. (this deters tree rats, too) Cactus fruits attract them too, but less so. They will eat citrus if really hungry. Tomatoes, melons and sweet corn might

Rodents -- Clean up anything -- including spilled bird feeder seed -- that can attracts rodents to your yard. Rodents attract coyotes as they make up at least 75% of a coyote diet. We have tree rats, so work on controlling them or the coyotes will do it for you.

2 - Do not let your cats and small dogs wander the neighborhood or stay out in your yard overnight, even if you have a fenced yard. They are food. Big dogs are safer, but can get in fights, especially in the spring when dens and pups are being defended.

http://stanleyparkecology.ca/conservation/co-existing-with-coyotes/pet-safety/

3 - If approached by a coyote, wave your arms, yell at it in a low-pitched voice, and throw things (sticks, small rocks) ... shaking those "rattle cans" with pebbles in them supposedly works well. Hazing them keeps them wary and respectfully at a distance. (a super-soaker with a tablespoon of ammonia and a full load of water works too)

http://stanleyparkecology.ca/wp-content/uploads/2012/02/The-Coyote-Shaker-July-2011.pdf

4 - Don't shriek, scream or run ... that looks and sounds like something wounded and edible.

5 - Keep small (pre-school and under children) under close supervision. Teach older (first grade and up) children what to do if they see a coyote. Groups of children are quite safe - too loud and active and numerous for a small predator to tangle with - unless the coyote is getting fed by humans.

RESOURCES:
http://www.urbancoyoteresearch.com/ - Chicago's research page.

http://phoenix.gov/recreation/coyotes.html - Phoenix City Info

www.azgfd.gov/pdfs/h_f/urban_coyote_faq.pdf? - AZ Fish and Game info

http://baynature.org/articles/keeping-the-peace-with-urban-coyotes/ - San Francisco resource page.

http://stanleyparkecology.ca/conservation/co-existing-with-coyotes/how-to-co-exist-with-coyotes - Vancouver

Around here they come up from the wash and from the golf course. It's where the bunnies are! OK, the cats and pekes too.

Coyotes have to eat and that's all they're trying to do. We have assigned the task of preventing them from eating things with the "family" label to two quite capable dogs. The dogs atr trained to be with kids when they're outside in the back. We have heard that although a pack hunter like the coyote is cagy and calculating around a dog, they will not mess one bit with a pair of German Shepherd sized dogs, and that bears out with what we see. I wouldn't expect that, being hungry, lights would bother coyotes much.

Depends on where the OP is... coyotes are very different in the east than the west, and different in the north than the south. They interbred (and interbreed) with local feral dogs, and some wolf species (like the red wolf). (There are 19 subspecies in the US)

In some areas of the country, they don't exceed 25 lbs. In others, they're in the 50-75lb range.

A big pack of northeastern coyotes will take down a lone german shephard easily.

Fences are the best bet.

We have coyotes that easily jump 6 foot fences. If there is food on the other side that is attractive enough, they are also quite competant diggers. I've not noticed that any kinds of lights deter them. They are pretty smart, and make fairly accurate judgements regarding their safety. In our area, there are folks who are willing to come out for free and shoot coyotes in the yard if you want. There is no season on them; they are considered a nuisance. So, if you end up having problems (and we never have had problems with all those around us), a hunter might be a good option. When we had large dogs, the coyotes kept their distance. Small dogs and cats in our neighborhood are very short-lived: either the coyotes, owls or hawks get them quickly.
Renais

Renasis, We've been here a few months now & I go out with the dogs at night with a flashlight to scan the area.(one does her business & straight back inside, the other is on a leash), My husband has no problem shooting a coyote if they come around.

We have also learned that they follow a circuit of sorts, & they aren't always in the area. We can hear either howling in the distance, or closer & the dogs in the area go nuts barking if something's around. They are my "alarms" to keep an extra eye open when our dogs go out at night. Thanks for the insight & suggestions. I'll still be glad when my husband has the house sided so he can put lights up. If for no other reason than it will help me see what's in the yard.

Lazy garden's list of tips is excellent!

Unfortunately, the coyotes in my area grew far too aggressive, chasing our kids to the school bus stop from home and coming towards my wife then snapping at her. When I learned of this, I stayed home one morning and watched as the Yotes gathered for their morning games. However, instead of the kids coming out the front door, I came from behind the house with my 12 GA. 870 loaded with #4 Buckshot and killed 3 of the 6 coyotes waiting outside. The survivors stayed away for a month but started coming back at night. I then introduced them to the red motion detector kill lights mounted on my trusty 870 and haven't seen or heard any Yotes for the past 3 months. BUT, they will be back and I will be ready!