A biodegradable polyamide fiber comprising: • A polyamide having a hygroscopicity delta, which is the difference between the moisture absorption rate of the polyamide after 24h at 30°C and 90% Relative Humidity (RH) and the moisture absorption rate of the polyamide after 24h at 20°C and 65% Relative Humidity (RH), of at least 4%, wherein the polyamide is a polyamide 5.X, X being an integer from 4 to 6; or a chemically modified polyamide by addition of hydrophilic modifiers; or by copolymerizing said polyamide with oxyethylene groups or polyetheramine groups; • A biodegradation agent, wherein the biodegradation agent comprises at least one of the following components: a. Chemo attractant or chemo taxis compound, being a sugar, a coumarin, a furanone or mixtures thereof, b. Glutaric acid or its derivative, c. Carboxylic acid compound, being hexadecanoic acid d. Biodegradable polymer, being chosen from polylactic acid, poly(lactic-co-glycolic acid), polypropylene carbonate, polycaprolactone, polyhydroxyalkanoate, chitosan, gluten, one or more aliphatic/aromatic polyesters such as polybutylene succinate, polybutylene succinate-adipate, polybutylene succinate-sebacate, or polybutylene terephthalate-coadipate, and mixtures thereof. e. Swelling agent, selected in the group consisting of natural fiber, cultured colloid, cyclo-dextrin, polylactic acid and mixtures thereof. • A polyamide having a hygroscopicity delta, which is the difference between the moisture absorption rate of the polyamide after 24h at 30°C and 90% Relative Humidity (RH) and the moisture absorption rate of the polyamide after 24h at 20°C and 65% Relative Humidity (RH), of at least 4%, wherein the polyamide is a polyamide 5.X, X being an integer from 4 to 6; or a chemically modified polyamide by addition of hydrophilic modifiers; or by copolymerizing said polyamide with oxyethylene groups or polyetheramine groups; • A biodegradation agent, wherein the biodegradation agent comprises at least one of the following components: a. Chemo attractant or chemo taxis compound, being a sugar, a coumarin, a furanone or mixtures thereof, b. Glutaric acid or its derivative, c. Carboxylic acid compound, being hexadecanoic acid d. Biodegradable polymer, being chosen from polylactic acid, poly(lactic-co-glycolic acid), polypropylene carbonate, polycaprolactone, polyhydroxyalkanoate, chitosan, gluten, one or more aliphatic/aromatic polyesters such as polybutylene succinate, polybutylene succinate-adipate, polybutylene succinate-sebacate, or polybutylene terephthalate-coadipate, and mixtures thereof. e. Swelling agent, selected in the group consisting of natural fiber, cultured colloid, cyclo-dextrin, polylactic acid and mixtures thereof. a. Chemo attractant or chemo taxis compound, being a sugar, a coumarin, a furanone or mixtures thereof, b. Glutaric acid or its derivative, c. Carboxylic acid compound, being hexadecanoic acid d. Biodegradable polymer, being chosen from polylactic acid, poly(lactic-co-glycolic acid), polypropylene carbonate, polycaprolactone, polyhydroxyalkanoate, chitosan, gluten, one or more aliphatic/aromatic polyesters such as polybutylene succinate, polybutylene succinate-adipate, polybutylene succinate-sebacate, or polybutylene terephthalate-coadipate, and mixtures thereof. e. Swelling agent, selected in the group consisting of natural fiber, cultured colloid, cyclo-dextrin, polylactic acid and mixtures thereof. <EOS>