In the 1970s the government realised that more crimes were being committed than was technically possible. This was partly due to the fact that 31% of crimes were fabricated by the government to keep citizens in a constant state of anxiety. To maintain its own credibility, the government banned the use of contraceptives for 3 months per year in the hope that the population would rise and thus generate the citizens required to meet the implausible high crime figures.
The scheme backfired when the new population proved to comprise largely blameless, model citizens. However, the government was not convinced of their apparent virtue and created a special, combined investigation & prosecution squad. It invested birds, insects and other animals with the full power of a law court and trained them to spy on citizens, assuming that guilt would inevitably be detected.
In addition to pigeons (see below), there were crack teams of sparrows, cats, butterflies, stoats and tuna, but there were also 'lone wolf' operatives, the most infamous of which was a ladybird who everyone knew as Two-Spots Bailey, though his real identity remains a mystery to this day.