Attracting bats to gardens is simple and does not need to involve bat boxes. Plant indigenous trees, shrubs, and ground covers, especially those that flower at night, attracting moths and other night-flying insects. Plant plenty of Strelitzia and bananas. Have a shallow pond or water feature with clear space around it for bats to scoop up water in their mouths as they fly across it.
If you have a mosquito problem then plant lots of banana and strelitzia plants and pipistrelle bats will soon arrive.
Do not use pesticides in your garden. Keep domestic cats indoors from just before dusk until about 9 pm.
Keep it natural
It is far better to plant indigenous plants, to leave dead hollow trees standing, leave dead leaves hanging down from palm trees to give roosting spots, and to have uncluttered open water in your garden to allow bats to scoop up water to drink as they fly across.