DEAR JOAN: I’ve found that providing the seeds birds like to eat, eliminating what is discarded, providing the type of bird feeders where birds can perch and eat, providing fresh water in a hummingbird feeder and removing the narrow slots to let more birds drink, and building a small birdbath with reflective rocks attracts more birds.

Birds are now eating almost 20 pounds a week of black oil sunflower seeds, 7 pounds of finch seed, and cracked corn.

How do birds spread the word? Do birds have food critics that communicate the best feeding sites?

Mark Evanoff, Union City

DEAR MARK: There is no bird equivalent of Yelp to comment on the quality of the food or the ambiance of the setting, but they do share the location on Twitter.

Actually, birds are in constant search of food, and they aren’t all that picky about the taste. If they like it, they eat it. If it’s not the type of food they eat, they ignore it.

While birds might not be all that discerning, they do have standards. If you have food that they really like, but don’t have it in a feeder that they care for, they can be slow in eating it. I have two different bird feeders and although I use the same seed in both feeders, the birds have an obvious preference for one over the other.

Likewise, you have to feed the birds what they prefer. House finches won’t bother with peanuts in the shell, but the crows and jays love them.

The birds find your feeders by sight. Flying high above your yard, they can see the feeder and recognize the food. They then swoop in to check it out, and if they like what they find — good food, preferred feeder, safe conditions — they’ll sound off with what bird experts call a “contact call.”

The contact calls usually are short chirps or whistles, and are the equivalent of humans playing Marco Polo. The birds are keeping in touch, but it’s also useful to signal the presence of food. Other birds hear the calls, see their cousins gathering in a spot and realize a food source has been located.

By the way, instead of converting a hummingbird feeder, you can purchase hanging water feeders. I have one in my yard that is popular with the birds.

While the birds aren’t commenting on your clever and thoughtful arrangement of feeders and choice of food, I’m sure if they did, you’d get five splats.

DEAR JOAN: What night time predator would invade a squirrel nest at night?

We have a large leafy squirrel nest extremely high up in our giant backyard oak tree. Tonight, nearing 10 p.m., when all was quiet and the squirrels were asleep, there was a large ruckus from high in the tree and then a lot of panicked chattering. A squirrel came racing down the tree.

There was a lot of rustling in the tree and down below. Because it was dark, we could see nothing. What could have happened?

Suzanne K., Danville

DEAR SUZANNE: My guess would be a great horned owl paid a visit. The usual tactic is for the owl to slam into the nest, causing the squirrels to run for cover and usually allowing the owl to pick off one of the slower moving squirrels.

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Use this form to submit questions. Photos should be mailed separately to jmorris@bayareanewsgroup.com.