Bat surveys are needed in the United Kingdom in case any development work affects the bats. Bats in U.K. are protected under section 9 of the Wildlife and Countryside Act 1981 (as amended) and regulation 39 of the Conservation (Natural Habitats &c.) (Amendment) regulations 2007. This protection comes in the wake of significant drop in the population of the bats during the last century. There are many reasons for their drop such as changes in ecological system, and unsafe habitats. When we mean changes in ecological system, it means disappearance of the preys which the bats used to feed on, declining hedgerows and woodlands. . Unsafe habitats stand for destruction of their roosts due to site development works. Hence, this only flying mammal has to be protected through legislation. The law imposes heavy fine or in some cases custodial sentence if:

1)  This European species are intentionally killed, injured or captured
2)  The roots of the bats are willfully disturbed or damaged
3)  The local distribution of the bats is in jeopardy due to disturbing acts 
4)  Capture or transport any part of the bats

All these do not just cause fines and custodial sentence but also long delay of the development work till the proper corrective measures are taken. Therefore, for any developer, it would be of paramount importance to know whether his proposed development is harming the bats and their roosts. Ecological consultants here can guide the entire development process by taking up thorough bat survey. Usually, there are six types of bat surveys and depending upon the nature of the development they are being undertaken by professional team guided by ecological consultant. Such surveys include:

1)  Initial assessment of habitat: The intention of this bat survey is to assess whether the site is able to sustain roosts and the feeding habitats of bats
2)  Building or bridge survey: ecological consultants have trained team that investigates whether buildings and bridges are able to house bats
3)  Such professional ecologists also survey the tress by climbing them and checking whether the trees are capable enough to allow the bats to make their roosts on it
4)  Another such survey is underground bat survey. In this survey, underground sits are investigated to find out whether bats are roosting there or not
5)  While undertaking dawn and dusk survey, ecologists often reach the site before dawn and after dusk to watch the bats leaving and returning to their roosts. The intention of this bat survey is to confirm what types of bats are residing there, how much the population is and from where they are coming and going
6)  In yet another bat survey which is called bat activity survey, ecological consultants use tools such as detectors and recorders to hear commuting and pillaging of bats. This type of study enables the analysis of bat echolocation calls which always vary from species to species

Apart from above mentioned laws, the Natural Environment and Rural Communities Act 2006 (NERC) also deems bats as species of "principle importance" under section 41 and section 40. This law mandates that in executing their functions, all the public bodies should have regard, so far as is consistent with the proper exercise of those functions, to the purpose of conserving biodiversity.