Dragonflies predict rain, fly backward, sign of Goodluck, (but nymph prey on fry)

It is rainy season again and Dragonfly nymph might be in our fishpond or fish tank, swimming with our fry and hunting it for later.
In case the number of your fry decreases, check for any sign of dragonfly nymph or any other predators. Scoop them and toss to your chicken :-)