I have amano shrimp in several tanks, and was also concerned the first time I saw this unusual behaviour.
This is one of my females in a previous tank, which caused quite a stir amongst the males. Eventually she climbed up a plant to release the eggs, and was surrounded by the penguin tetras who made the most of the free meal.
I had considered trying to breed these shrimp, as I already have some experience with brackish tanks, but after researching it I decided that it was difficult with very little chance of success.
The second pic is one of my little fellas stealing an entire algae wafer from the BN plec. Cheeky monkey.