In construction of an Mbari house, it is the priest who coordinates the selection of Mbari workers called "Ndi Mgbe" and the work is not done by every able-bodied man and woman. Rather the priest begins by inviting a diviner (dibia) to do the selection of Mbari workers.
As soon as the diviner arrives a goat is killed as a sign of warm reception and hospitality. When the diviner has finished eating and drinking, he starts his job with the priest who has already identified a suitable site for the erection of an Mbari house.
Then both the priest and the diviner walk from one area of the village to another across the entire community, going from one house to another to recruit men and women, old and young , at least each from a compound under strict divination.
How Mbari workers are selected
In the process of selection there is no age or sex discrimination. But workers between the ages of twelve and forty years are selected because of their strength and productivity. Nobody dares disobey the divine call as such might spell doom or attract the anger of the spirit-god (agbara). Normally, forty people are selected for the job as Mbari workers (ndi mgbe). But it should not be less than twenty in number.
According to tradition, the selected Mbari workers (ndi mgbe) must stay twenty-four days in a special house built for them in the compound of the priest before the commencement of the work. It is a sort of confinement or fattening seclusion but not for marriage this time.
Thus, the Mbari workers (ndi mgbe) are withdrawn from domestic chores and normal social activities from their families and community respectively. This seclusion is a period of rest, relaxation and recreation as well as enjoyment when the selected Mbari workers (ndi mgbe) get so well fed for the period of twenty-four days to make them become robust and strong for the work.
Thus, they eat every kind of foods. The eat meat as much as they could, and drink wine to their satisfaction daily. Unlike in the fattening seclusion for marriage which only involves maidens, the fattening seclusion for Mbari construction involves both selected men and women of different ages below forty years.
Secondly, during fattening seclusion for marriage, maidens are not permitted to go beyond the sitting room; but in the case of fattening seclusion for Mbari construction, workers occasionally go out to salute the gods in whose Mbari is to be constructed. But before they are go out, a metal gong (igbugbo) or "ogene" is sounded or drummed to signify that they are passing so that any passer-by will go into hiding as failure to do so will attract to the offender a fine of one goat.
Besides this special outing, the Mbari workers (ndi mgbe) are not to be seen again outside the fattening house till after twenty-four days. This period is also described as a period of sanctification. For their body decoration during the period is made of cam wood dye (uhie) which they lavishly rub on their bodies.
None-the-less, where a person rejects the call to work as an Mbari worker (ndi mgbe), he or she has to redeem him or herself with money. But if it is a teenager, his or her parents will redeem him or her with money to avoid the anger of the gods.
In addition, if a married woman is selected as one of the Mbari workers (ndi mgbe) and her husband is jealous of her meddling with another man, he could pay certain amount of money to the priest to enable him spend his nights within the precincts of Mbari in order to be with his wife on daily basis till the completion of the construction of the project.
After the twenty-four days of fattening seclusion and sanctification, the work then commences. It is expedient to reiterate that before the commencement of the twenty-four days of fattening seclusion, the priest goes round the community to solicit the assistance of individual persons and families for generous donation of building materials.
When the work commences in full, the Mbari workers (ndi mgbe) will first of all start with fencing of the Mbari enclosure. The fence, normally made of palm fronds is about twelve feet high and thickly compacted that nobody could even see a needle inside the compound.
When fencing is completed, the mbari workers (ndi mgbe) will then relocate to the Mbari compound. It is there they will stay till the main Mbari building is completed which might take one and half years or two. Before the advent of Christianity and western civilization some people could stay there after the Mbari house has been completed.
As soon as the Mbari seclusion is completed, the work then commences. Besides the building materials which members of the community have donated to the priest on request for Mbari construction, there are however certain building materials which are forbidden for the public or members of the community to supply except by the Mbari workers (ndi mgbe).
One of such materials is anthill clay (ozuru). It is not collected in the day time but at night between the hours of 9pm and 1am the next morning during which the Mbari workers (ndi mgbe) will move out in organized groups and sound or drum their metal gong (igbugbo or ogene) as they move along the tortuous foot-path to announce their presence.
Famous artists from neighboring villages are commissioned to mould and model the Mbari images of gods and their messengers. The renowned artists decorate the centre of the Mbari with artistic drawings in lucid colors. The main reason of kneading or pounding of the clay to pastry form is to produce smooth and durable and life-size unbaked clay figures of gods and god's messengers in form of animals, snakes, insects, e.t.c.