You're someone who is worried about bats. Maybe you've heard some news reports about white-nose syndrome. Maybe you've noticed that our blind, furry little friends have been mysteriously MIA from your property in recent years. Maybe you read the article about biologist Tom Kunz, who has dedicated his life to understanding little brown bats and the various threats to them, in the Fall 2011 issue of OnEarth. Maybe you're aware that some experts fear that Myotis lucifugus could be extinct by 2025.

You want to help. And, fortunately, you can.

If you did happen to read OnEarth Editor-at-Large Ted Genoways' article, then you know that Kunz and his team at the Center for Ecology and Conservation Biology at Boston University have been experimenting with "roost modules" -- basic wooden boxes that host maternity colonies in the summer months. These can help keep bats warm enough to avoid contracting the disease, which can't survive in temperatures above 68 degrees Fahrenheit.

According to Kunz, the modules are pretty easy to assemble if you have some basic DIY skills.

How easy?

"The design is so simple," Kunz told Genoways, "that teachers and Boy Scout leaders could have kids make them."

Many of you wrote in to say, basically: Great that they're so simple to build. Tell us how!

I volunteered.

Turns out it's not quite so simple.

Sure, the roost modules that Kunz's team installs could be built by Scouts, but installation is actually a bit of a challenge, even for someone like me who spent a post-college year framing houses and scurrying across roofs. They're pretty darn heavy and cumbersome, and you can't just go and hang them anywhere. Odds are, you don't have a place on your property to properly install the Kunz plan modules, and even if you did, you'd have a heck of a time getting them into place without renting a "cherry picker." (Trust me -- I tried, and I feel lucky that I'm not now wearing a cast on some appendage.)

But that doesn't mean we just throw in the towel, right?

I worked with Nate Fuller of Kunz's "Bat Lab" to come up with a good DIY roost module plan for regular folks like us to build and install, and to offer suggestions for both the more- and less-ambitious prospective bat-hosts out there. As we sorted our way through different ideas, Fuller and I settled on a range of options -- for those without a lick of carpentry know-how all the way to the DIY superstars and general contractors among you.

And, finally, for the great many of you who fall somewhere in the middle -- handy with a drill but not exactly Bob Vila -- I've gone ahead and put some elaborate, step-by-step directions (with photos!) into this PDF, which you can download and print out or load onto your iPad or whatever you'd like.

Now: for those of you who just want the easiest, simplest route to a home for bats, I'd suggest taking ...

The Easy Way Out: Buy or build a simple bat house.

This is best if:

• You don't have a barn or attic with an established bat colony.
• You don't have a ton of time to devote to a DIY project.

The Kunz team's modules are intended to be installed in locations where maternity colonies are already established. This usually means old barns or vented attics, and they're most often in places that are tough to access, like the ridge beam and rafters 40 feet above the ground.

But over time, bats will find comfortable places to roost. And a bat box is specially designed for bat comfort. They're also relatively cheap to buy (here are a few that range from $75-$150), or pretty simple to build. The Bat Conservation International site has pretty much all the information you could ever need about bat houses, from detailed DIY plans to a list of certified vendors to tips on installation and on how to attract bats to your newly opened bat condos.

The Organization for Bat Conservation also has great resources for you DIY types, with downloadable plans and a 10-minute video that walks you through the whole project step-by-step.

On the far other extreme of the DIY spectrum -- if you happen to be simultaneously a Toscanini of the Sawzall, a Picasso of the caulk gun, and an Andretti of the cherry picker -- you could take a crack at building and installing one of the original designs.

For Experts Only: Build the heavy-duty Kunz plan module.

This is best if:

• You have a barn or attic with an established maternity roost colony.
• You've got decent to advanced DIY skills.
• You've got access to a cherry picker or mechnical lift, and are comfortable working in high places and tough conditions.

Now: if you're going with this option, I'm going to trust that you're already pretty handy and not afraid of heights. And rather then run down step-by-step how to build one, I'm just going to provide some plans and photos, and trust that you can figure things out from there.

These designs were drawn by Scott Reynolds for Kunz's Bat Lab. As you can see, these roost modules have a slanted top, to fit right up against the roof of a barn or attic.

Installation:

Typically, these are installed in pairs, though that's not entirely necessary. If your barn has a ridge beam, the 24" wall should butt up flush against it. If there is no ridge beam, then you could fashion some horizontal braces out of 2" x 6" pieces anchored to the rafters. Like so:

Of course, as any good builder will tell you -- you do whatever works. I've seen these installed with strapties and anchors. When I brought one of the Kunz lab-designed modules to a friendly OnEarth reader's farm (more on that in the future), we managed to wrestle it up a ladder and onto the second floor, but couldn't get it to the peak. We had to settle for propping it up on a cross-beam and a spare post, with some metal braces to secure it.

Generally speaking, the higher the better. And the closer to existing bat roosts, the better. But do the best you can.

And most importantly, be careful up there.

Once again, if the heavy-duty original designs seem a little too ambitious, and the store-bought bat houses not adventurous enough, you might want to try to build the more modular designs that I came up with. Instructions are attached here in this PDF.

A note on timing: It's best to get these roost modules in place before the bats come out of hibernation and start settling into their colonies. If they're already setting up shop and then suddenly there's this big mysterious wooden structure -- even if it's a beautiful bat mansion -- they might get spooked and head off for someone else's barn.

Because of the early warmth this Spring (2012), depending on your area, the bats may already be coming out of hibernation. Fuller recommends doing an "emergence count" before hanging your roost module to see if it's too late this year. There are tips for how to do an emergence count here (about halfway down the page). Fuller says that if there are less than 10 or so, it should be fine to install the roost module. If there are more, then hold onto it for now and hang it in the Fall.

Of course, you might not have any significant bat activity in your barn or attic or wherever else you'd like to install your roost module. That doesn't mean they won't find it. Consult the tips from Bat Conservation International (PDF) about how to attract bats to a bat house. Same principles apply.