Tree can be a good place for bat box but the tree need to be right.
Dead snags make the best as they give the bat a great landing space.
Some other time
BAT HOUSE INSTALLATION TIPS
- Bat houses should be mounted in an area that gets 6-8 hours of direct sunlight (facing either East or South).
- To the extent possible, locate all houses 20 to 30 feet from tree branches or other obstacles and 12 to 20 feet above ground (or above the tallest vegetation beneath the bat house).
- Locate you bat house near the largest water source in the area. These locations are typically the most successful, as are those in or adjacent to the most diverse or natural vegetation. The best locations are along streams, rivers, lakes or forests because these are natural bat flyways