My darlingi are still small but one the other day was attacking the paintbrush.
I'm sure most of them are more on the defensive / aggressive side.
I only have L. parahybana, so I can only comment on them. They grow very quick and get huge. When they get some size, you need a reliable food source. One of my LPs love to throw up a threat pose anytime I open the enclosure. Will run and grab the tweezers with force. The venom is not the most potent but those fangs get very large. I'm guessing they can cause some damage.