At the Wye Marsh, while dip-netting with children, I make a big deal of carrying any animals they catch into the collection basins. I mean, I try to show they are not dangerous and can be handled without fear. I have one exception; catfish, which have sharp spines in their pectoral and dorsal fins and can draw blood. I still carry them but warn the visitors not too.
Now, I may have another exception, the dobsonfly larva.
In the second picture you can see the larva is longer than my finger is wide and in the first, you can see the mandibles. From Wikipedia:
Hellgrammites [another common name for the larva] live under rocks at the bottoms of lakes, streams and rivers, and prey on other insect larvae with the short sharp pincers on their heads, with which they can also inflict painful bites on humans.
More info to be found here.
I wasn’t bitten but was cautious and nervous while carrying them. After reading the above, I may set them on leaves or the like to transport them.
I don’t know if I need to tell my reader(s) that I do carry leeches in my bare hands to the basins. I do tend to pass them from hand to hand so they don’t have time to stick. I think they are too upset or afraid to concern themselves with food but I, at least, feel better giving them a bumpy ride.
Finally, all captured critters are released at the end of the session.