An "implant and forget" device for interacting with biota after a pre-established time period. Preferably, the biota are fauna and more particularly fish. In select embodiments, the device comprises packaging enclosing apparatus for timing interaction via opening the packaging. In select embodiments of the present invention, the device is a sealed capsule inserted in fish. Embodiments of the present invention are implanted in triploid grass carp (Ctenopharyngodon idella) to facilitate control of aquatic weeds in bodies of water. When the carp have been in the water for a pre-established approximate period of time, toxins in the device are dispensed via long term bioerosion of the sealed opening in the packaging. Otherwise, the carp may destroy all vegetation and harm the aquatic environment for other aquatic life. Several alternative bioerodible seal configurations are provided as embodiments.