You can tell what scorpion is more poisonous by looking at the end where the stinger is, if it is as fat as the rest of the tail it is not that bad, pain and discomfort, if the tail is thin, specially the last bit with a longish stinger, that one is more toxic and may need medical attention.
Arround the area of Durango the ones to look out for are the "blond" ones, the "gueros" they are poisonus, one thing that we do when we are in tierra caliente is to never put on any foot weare that has been on the floor over night with out first having banged it on the floor, same goes for hanging towels in batrooms and clothing in general, good habit I picked up from my father, many times I have disloged a sleeping scorpion or black widow, scorpions will glow greenish with an ultra violet light.
The other item we do is pull the covers and sheets of beds to check for "you guessed it" scorpions, spiders, and one time a snake when we happen to stay at hotels in areas where there are night crawlers when we need to go to towns with out the RV.
navegator