Abstract: Cryptic species are a major challenge for alpha-taxonomy in ants. Their reliable identification requires the application of elaborate methods such as Numeric Morphology-Based Alpha-Taxonomy or analysis of Dna and cuticular hydrocarbons. Complications caused by intraspecific polymorphism and interspecific hybridisation necessitate integrating these methods in multi-source approaches. The frequency of cryptic species was estimated in three ant genera subject to a thorough analysis as ± 46% of about 94 Palaearctic Lasius species, ± 43% of about 67 Palaearctic Formica species and ± 52% of about 77 Cardiocondyla species worldwide. Similarly high ratios were predicted for other ant genera, although testable data are missing. Cryptic biodiversity is not evenly distributed within the evaluated ant genera. The indicative value of the following investigation methods was assessed in ants: Morphology-Based Alpha-Taxonomy (MOBAT), Numeric Mobat (NUMOBAT), analysis of nuclear and mitochondrial Dna, cuticular hydrocarbons, pheromones, allozymes, karyotypes, ethology, and ecology. Numobat is arguably the "backbone" of a testable integrative taxonomy, the deciding link to Zoological Nomenclature, the only useable method for DNA-degraded specimens and the only method to examine vouchers in which no damage is allowed. The unacceptably high ratios of paraphyly in mtDNA barcoding forbid its application as primary decision finder. In conclusion, no single method but only an integrative, multi-source alphataxonomy offers the most convincing approach towards recognition of real biodiversity.