I just got an email from someone about a lot of rodenticide bait boxes in an area in Santa Fe. The company that put them there is totally unqualified in common sense. In New Mexico, we have approximately 107 species of fleas (I counted them). Of that number, about a third are known or possible vectors of the plague. Most rodents, including deer mice and pack rats have fleas on them. There are about two dozen species of fleas that like feeding on rodents and about a third of them are vectors of the plague. What happens is that when a rodent eats the rodenticide in the bait station, they eventually die. When the dead rodent’s body cools down, any ectoparasites on it, including fleas and mites, will leave the dead rodent and look for a meal. If there are pets around, they will get on them and they can get on any humans in the area. When I was IPM Manager for Santa Fe, I wouldn’t allow any rodenticides to be used on city property. The same thing when I was the IPM Tech at UNM. No rodenticides on campus.
Anyone in the pest business should know this info and not use rodenticides. In fact, they should be illegal to use wherever plague fleas live. Anybody can control rodents with traps if necessary. Rodenticides are never necessary. I would bet most of the plague cases in NM came from fleas that left dead rodents and got on people. If you have an exterminator and they want to use rodenticides, tell them no. If they insist, fire them. If you live in a city, town, county, HOA or anywhere that rodenticides are used, have them removed and not replaced. Protecting people from the plague is more important than putting out those black boxes which just makes it look like the exterminator is doing something. This is very relevant if you live in any state where plague is possible or even other states. What if a rodent has hantavirus and dies in a house where it can’t be found? That could be problematic.
Also, birds and other animals that feed on dead animals can be seriously affected if they eat a rodent that was poisoned. Some people even put rodenticides in remote areas hoping to kill coyotes.
Don’t allow rodenticides to be used anywhere