The extreme case of the shrimp iron filings experiment.
Shrimp picked up iron filings during moult and were then magnetically controlled from outside their holding aquarium.
Seriously and not just another fantasmagorical bamboozling enigma.
Yes – omniverous shrimp, as benthic (bottom) trash feeders, can hoover up most anything.
Want them to grow faster? Increase marine protein level in feed.