Let's start with a very clear message: The use of urethane spray foam is NOT to be used in a proper, humane, bat exclusion project.
We started receiving messages late last night which continued into today, regarding the improper bat exclusion project performed by a local pest control company at the Sanctuary Loft Apartments in San Marcos, TX and the subsequent trapping and killing of countless bats that inhabited their parking garage expansion joints.
You can read the story KXAN published here:
With over 24 years of providing commercial, humane, bat control throughout Texas, we unfortunately have seen these improper techniques used by many other companies and property managers. After reading this article we have come away with a few points we'd like to make:
- Bats remain very close to their entrance/exit points (ie: where sealing takes place). When using an expanding spray foam, such as that pest control company did, you almost certainly will trap the bats. This foam expands into the crevices they inhabit and sticks to them.
- Bat Conservation International (http://www.batcon.org/), a leading authority on all things bats and Austin Bat Refuge (https://austinbatrefuge.org/) both do not recommend the use of expanding urethane spray foam for use in bat control. They approve of other sealing methods/products which are not harmful to the bats. Urethane spray foam may be fast to use, but it is a hard-to-control product and degrades very quickly as well, especially when exposed to sunlight and will not "move" with the building, just to name a few reasons why it is not a commercially viable product to use.
- If a pest control company proposes to "do the work at night, so all the bats are gone..." - they are inexperienced at the very best. The reasons this method doesn't work is that not all bats leave the roost to feed every night and/or at the same time. Up to 25% of a bat colony can remain in their roost at night, while the others are off feeding.
- A proper bat exclusion should be performed during daylight hours, with the professional use of backing rod, urethane caulking and bat excluders. Due to water flow, some sealant methods will include a hardware cloth type material and again bat excluders. Backing rod is the barrier between roosting bats and the urethane caulking. Bat excluders are one-way doors that allow the bats to leave, but not reenter their roost and should be placed at least every 10' along areas were bats are roosting and left up for at least 5-7 days, and when you can verify all bats have left the roost.
- Property managers expect and believe that pest control operators know what they're doing when it comes to bat exclusions and that they are educated in proper exclusion methods. However, at the time I took my certified applicator test, there were no questions on the test regarding bats and the subject was barely mentioned in the pest control manuals. This really is a specialized field. Do not expect your average pest control providers to know how to perform this work! Remember, a good majority of their time is spent on bugs, spraying weeds, etc.
- As you would with any contractor you hire, its a good idea to get multiple bids, base your awarded contractor on a history of verified, successful projects, not just a low price and contact a third party for confirmation on techniques as well as with any questions you may have. Bat Conservation International and Austin Bat Refuge are both great resources for this step.