Animal housing unit

The design is the visual features of the animal housing unit shown in solid lines in the drawings, whether those features are features of one of shape, configuration, ornament or pattern or are a combination of any of these features. The portions shown in stippled lines do not form part of the design.Figure 1 is a top front perspective view of a first variant of an animal housing;Figure 2 is a top rear perspective view thereof;Figure 3 is a first side elevation view thereof;Figure 4 is a front elevation view thereof;Figure 5 is a second side elevation view thereof;Figure 6 is a rear elevation view thereof;Figure 7 is a top plan view thereof;Figure 8 is a top front perspective view of a second variant of an animal housing;Figure 9 is a top rear perspective view thereof;Figure 10 is a first side elevation view thereof;Figure 11 is a front elevation view thereof;Figure 12 is a second side elevation view thereof;Figure 13 is a rear elevation view thereof;Figure 14 is a top plan view thereof.