Mine are out in the open and noone has @%$#ed with them. The way screamers work is they are drawn by heat.
The way heat works is generally making noise. Using crafting stations all generate some heat. The chem station the most.
Resource gathering is a big heat generator too, especially with an augur or chainsaw.
This isn't heat in the literal sense, which I think many people take it as, but the figurative sense of "drawing heat to yourself"
So yes, even the dew collectors produce heat, which while it still doesn't make a lot of sense for them to outside of the obvious reason of limiting how many we spam, I think of it as signs of activity and civilization produce heat.
Some people would consider it a bonus, and although I generally do, I still want the ability to control when a screamer horde starts, it is a little annoying when you have planned to do some gardening and uninvited guests show up. A half a dozen or so dew collectors seems to be ok.