In some examples, a method to monitor an animal may include determining a physiological status of the animal based on a tattoo that includes intelligent ink injected into skin of the animal. The method may also include recording the physiological status of the animal. The method may also include, in response to the physiological status indicating a physiological event or condition, triggering an alert to address the physiological event or condition.

Various embodiments include an actuated projectile launcher, including: a base structure; a projectile support, and a holding area from which a projectile launches; propulsion wheels selectively driven to rotate; and support arms, each supporting at a first end thereof a separate one of the propulsion wheels and being supported at an opposed second end thereof by the base structure. The support arms are configured to move the propulsion wheels between an expanded position and a contracted position, in which the propulsion wheels are closer to one another in the contracted position as compared to the expanded position. The movement of the propulsion wheels toward the contracted position brings the propulsion wheels into engagement with the projectile and drives the projectile from the holding area.

Symbologies suitable for use marking codes on rodent tails are disclosed, for both machine-readable and human-readable codes, and those codes combined. Codes comprising both a human-readable and a machine-readable portion may associate with an animal ID within one study, and a study ID within a vivarium, respectively. A human-readable code uses a subset of an alphanumeric symbol set. A machine-readable code uses a vine-code with a visible spine aligned with the rodent's tail. Both symbologies support a system for deleting symbols and correcting codes marked in error. Both symbologies use symbol sets comprising only horizontal and vertical line segments. Both symbologies include a sparse mapping table for mapping marking codes to animal and study ID, and for error detection and for code re-use.