The Pink Prowler Oonops domesticus
Oonops domesticus or the Pink Prowler is one of several spiders that are virtually exclusive to houses. In warmer parts of Europe this tiny, 2mm, pink spider lives under stones, amongst leaf-litter and the like. It has an odd way of slowly walking with its front legs out-stretched, interspersed with short bursts of running. Its small size and pinkish colour make it difficult to spot, particularly because it is nocturnal.
During the day, it hides away in a silken cell behind furniture, curtains, picture frames, etc. As it walks across the ceiling it may come across potential prey. These are often initially stroked by the spider; it then darts forward and bite its victim that makes no attempt to get away. Should its prey struggle, Oonops will either pounce on it or hold it down with the claws of its front feet. The only other spider known to do this is also a domestic species, the Spitting Spider (Scytodes).