"DEMNA-DNE : Exotic animal occurrences in Wallonia, Belgium" is a presence-only dataset, aggregating non-native fauna occurrences from various data sources maintained by the Département de l’Étude du Milieu Naturel et Agricole (SPW – DGARNE - DEMNA). Original data sources compiled (listed below) are heterogeneous in the sense that they result from surveys performed by a variety of actors : Department officers, citizen observations, external partners. Geo-referencing should be carefuly done considering the term ‘FootprintWKT’ when given, as the dataset includes both grid-derived and point data. Main original data sources gathered are the following : "Encodage en ligne OFFH" is the core encoding module of the Département de l’Étude du Milieu Naturel et Agricole (SPW – DGARNE - DEMNA). This encoding tool (http://observatoire.biodiversite.wallonie.be/encodage) is used by the department's officers, but also by third-party users registered in the system. "Enquêtes OFFH" are variants of the previous tool, specifically dedicated to survey exotic or invasive species. These specific surveys, set up by the Cellule interdépartementale Espèces invasives (CiEi), are open to the general public and can be found at :http://observatoire.biodiversite.wallonie.be/enquetes . "Ecrevisses invasives" is a set of exotic crayfish data compiled and shared by Roger Cammaerts as part of the monitoring of crayfish populations in Wallonia. All records have been validated by the department experts based on a set of rules relying on pictures, the observer’s taxonomic expertise, ecological relevance or additional information requested to the observer (see DC term :IdentificationVerificationStatus). Please notice that since 2022, the Early Warning dataset [DOI10.15468/dc2dyg] allows daily-updated access to some invasive species records and should be considered as complementary to this present dataset, without duplicates. This dataset content is under a CC-BY license. Please make sure to quote the Département de l’Étude du Milieu Naturel et Agricole (SPW – DGARNE - DEMNA) if you make any use of the data. Please contact the department for additional information about the dataset or about our biodiversity/IAS related activities. Returns and comments are highly appreciated.