A briquette, which is easily pierceable and supportable, comprises compacted particulate material and has an outer region (1) and an inner region (2), said inner region (2) being provided with a well (3) having a diameter which decreases progressively in a non-linear relationship with increasing distance from the top of the well such that the sides of the well extend convexly into the well. The briquette, preferably, is a rodenticide block although it may, instead, be a block for sanitary, and/or domestic use. The briquette may be manufactured by compacting particulate material into the nip between a first rotating roll, having a surface provided with a suitable mould, and a second, counter-rotating roll.