Over the years I've had a lot of people interested in my animals, but that's all they were - just interested. Some people have never seen animals in real life. When I used to show rabbits, I had people follow me to the parking lot of the show ground, because they could see rabbits in the back of my car, and could not figure out what they were, and really wanted to know. I was always friendly and showed them the rabbits, or in some cases GOATS (Yes, I used to haul goats in my car but shhhh, don't tell my husband!

) because these poor people had never had the chance to pet a bunny or a goat.
Where I live now, people frequently stop on the highway to stare in amazement at the animals. They take pictures and so on. I feel really sad for them, that they have never been around horses or goats and think it's so odd they should take a picture. And I've done it too!!! There is a nearby ranch that has the most stunningly beautiful longhorn steers I have ever seen in my life. I have stopped to take pictures of those amazing animals a couple of times, and I hope to paint a picture of those steers for my living room.
It seems highly unlikely to me that a neighbor would have nefarious plans about your chickens. It is entirely possible that he simply had no idea what those were. Very sadly, there are many people these days who have never been close to an animal, except for maybe a cat or a dog.