perhaps

The apparently featureless shape in the air turned towards it and drifted a few inches closer. When nothing more happened, it turned again and fluttered quietly back down into the hollow.
“Could it tell I was scared?” the pony asked uneasily.
“You reacted just right,” Grandma said soothingly. “Startled suspicion at first, and then just curiosity, and then another start when it made that jump. It’s about what they’d expect from creatures that would be hanging around the hollow now. We’re like cows to them. They can’t tell what things are by their looks, like we do—”
But her tone was thoughtful, and she was more shaken than she would have cared to let the pony notice. There had been something indescribably menacing and self-assured in the Halpa’s gesture. Almost certainly, it had only been trying to draw a reaction of hostile intelligence from them, probing, perhaps, for the presence of weapons that might be dangerous to its kind.
But there was a chance—a tiny but appalling chance—that the things had developed some drastically new form of attack since their last breakthrough, and that they already d